library(bookdown)

1 Introduction

The occurrence of poverty has significant social and economic effects, and the way it is defined and measured poverty affects strategies to combat it. Therefore, this issue is widely discussed both in the literature and in the political arena. It is now believed that it is not merely an inability to meet basic needs essential for physical survival, but rather an involuntary lack of material, social and cultural resources deemed necessary by society as a whole. Thus, simple one-dimensional measures, based only on income, may not be sufficient to correctly identify poor people (Coromaldi, Zoli, 2007; Siani, 2015 ).

Therefore, the aim of this article is to verify the research hypothesis that, in the case of Poland, the multidimensional analysis of poverty cannot be replaced with a measure based solely on income, without significant differences in the identification of the poor. The study is based on an analogous analysis of poverty Italy, presented in the article Coromaldi and Zola (2007).

The first part briefly presents the concept of poverty measurement in economic literature, along with the results of analyzes of empirical articles relevant to the research hypothesis. The research methodology is then described after the data set used has been presented. Then, the results of the analysis and conclusions from the study are presented.

2 Literature review

Currently, it is believed that poverty should be treated as a multidimensional phenomenon, more related to a person’s standard of living, not only to the amount of income. And while traditional methods have the advantage of being easy to compute, the univariate approach has been challenged in recent decades. Mainly due to the fact that they do not include other non-monetary variables relevant to determining the needs of households. In addition, income-based methods often mean that such elements as savings, informal income, family benefits or the consumption of public services are not taken into account or are not very reliable, which may distort the results obtained. It is also worth noting that income is not a measure of real living conditions, but only a resource that enables the achievement of prosperity. In other words, actual poverty can only be determined by means of multivariate analysis, but is related to financial poverty, and therefore income-based measures are still widely used as poverty measures. In this context, the economic literature asks how far such financial measures can replace multidimensional measures (Coromaldi, Zoli, 2007; Dekkers 2003).

3 Methodology

For the analysis of poverty in this study, principal components analysis were used, after prior transformation of categorical variables using the optimal scaling method. The methodology used is analogous to that adopted in the article by Coromaldi and Zola (2007). It is based on the premise that if poverty is defined as a state in which several deficiencies in different areas accumulate, these deficiencies can be seen as a hidden dimension of poverty. One of the statistical techniques used to identify the hidden, invisible structures of a data set is the aforementioned principal components analysis. Each hidden variable is weighted by a function of the original variables. The more the observed variables are correlated with each other, the more likely they are to represent the same dimension of scarcity.

4 Data

The data set used was based on the data from the Social Diagnosis study. The data included in the study refer to 2015.

library(readxl) 
library(stats)
#Set working directory
setwd("/Users/nehrebeckiwp.pl/Desktop/UL2")
data <- read_excel("Sondaz_Spol_1.xlsx")
# check number of observations (rows and columns)
dim(data)
## [1] 1161   20

The variables used to determine the poverty dimensions concern:

The variable used to measure income poverty is monthly per capita household income.

Other variables used in the analysis are the following sociodemographic variables, situation on the labor market, size of the place of residence.

# verification of type of variables 
str(data)
## tibble [1,161 × 20] (S3: tbl_df/tbl/data.frame)
##  $ fla_area       : num [1:1161] 23.3 20 35 30 50 ...
##  $ car            : num [1:1161] 0.00985 0.00985 0.00985 0.00985 0.99596 ...
##  $ v_colour       : num [1:1161] 1 1 1 1 1 1 1 1 1 1 ...
##  $ video_player   : num [1:1161] 0 0 0 0 0 1 1 0 1 0 ...
##  $ saelie         : num [1:1161] -3.77e-15 -3.77e-15 -3.77e-15 1.00 -3.77e-15 ...
##  $ cd_player      : num [1:1161] -6.66e-15 -6.66e-15 -6.66e-15 -6.66e-15 -6.66e-15 ...
##  $ compuer        : num [1:1161] 4.55e-15 4.55e-15 4.55e-15 4.55e-15 4.55e-15 ...
##  $ inerne         : num [1:1161] 2.22e-15 2.22e-15 2.22e-15 2.22e-15 2.22e-15 ...
##  $ washing        : num [1:1161] 1.00 1.00 1.00 2.22e-15 2.22e-15 ...
##  $ machine        : num [1:1161] -1.62e-15 -1.62e-15 -1.62e-15 -1.62e-15 -1.62e-15 ...
##  $ dishwasher     : num [1:1161] 2.78e-17 2.78e-17 2.78e-17 2.78e-17 2.78e-17 ...
##  $ microwave      : num [1:1161] 3.11e-15 3.11e-15 3.11e-15 3.11e-15 3.11e-15 ...
##  $ freezer        : num [1:1161] 1.17e-15 1.17e-15 1.17e-15 1.00 1.00 ...
##  $ el             : num [1:1161] -9.55e-15 -9.55e-15 -9.55e-15 -9.55e-15 1.00 ...
##  $ no_food_clohes : num [1:1161] 1 1 1 1 1 ...
##  $ no_reamen      : num [1:1161] 1 1 1 1 1 ...
##  $ no_educaion    : num [1:1161] 1 1 1 1 1 ...
##  $ no_aparmen     : num [1:1161] 1 1 1 1 1 ...
##  $ siuaion_fin    : num [1:1161] 0.0487 0.0487 0.0487 0.0487 0.0487 ...
##  $ aparmen_siuaion: num [1:1161] 4.77 2.39 1.83 4.77 4.77 ...

The elements of PCA with individual functions is normalization of data.

#install.packages("caret")
library(caret)
## Loading required package: lattice
## Loading required package: ggplot2
preproc <- preProcess(data, method=c("center", "scale"))
data.s <- predict(preproc, data)
 summary(data.s)
##     fla_area            car             v_colour        video_player    
##  Min.   :-1.2824   Min.   :-4.5385   Min.   :-6.3584   Min.   :-1.4081  
##  1st Qu.:-0.6537   1st Qu.:-1.1958   1st Qu.: 0.1571   1st Qu.:-1.4081  
##  Median :-0.2709   Median : 0.8135   Median : 0.1571   Median : 0.7095  
##  Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000  
##  3rd Qu.: 0.3350   3rd Qu.: 0.8135   3rd Qu.: 0.1571   3rd Qu.: 0.7095  
##  Max.   :10.0626   Max.   : 3.0691   Max.   : 0.1571   Max.   : 0.7095  
##      saelie          cd_player          compuer            inerne       
##  Min.   :-0.6688   Min.   :-1.1885   Min.   :-1.1021   Min.   :-0.9321  
##  1st Qu.:-0.6688   1st Qu.:-1.1885   1st Qu.:-1.1021   1st Qu.:-0.9321  
##  Median :-0.6688   Median : 0.8407   Median : 0.9066   Median :-0.9321  
##  Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000  
##  3rd Qu.: 1.4940   3rd Qu.: 0.8407   3rd Qu.: 0.9066   3rd Qu.: 1.0719  
##  Max.   : 1.4940   Max.   : 0.8407   Max.   : 0.9066   Max.   : 1.0719  
##     washing           machine          dishwasher        microwave      
##  Min.   :-2.6994   Min.   :-0.3152   Min.   :-0.3425   Min.   :-0.9321  
##  1st Qu.: 0.3701   1st Qu.:-0.3152   1st Qu.:-0.3425   1st Qu.:-0.9321  
##  Median : 0.3701   Median :-0.3152   Median :-0.3425   Median :-0.9321  
##  Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000  
##  3rd Qu.: 0.3701   3rd Qu.:-0.3152   3rd Qu.:-0.3425   3rd Qu.: 1.0719  
##  Max.   : 0.3701   Max.   : 3.1699   Max.   : 2.9170   Max.   : 1.0719  
##     freezer              el         no_food_clohes      no_reamen      
##  Min.   :-0.6809   Min.   :-1.861   Min.   :-1.4791   Min.   :-1.5862  
##  1st Qu.:-0.6809   1st Qu.: 0.537   1st Qu.:-1.4791   1st Qu.:-1.5862  
##  Median :-0.6809   Median : 0.537   Median : 0.6755   Median : 0.6299  
##  Mean   : 0.0000   Mean   : 0.000   Mean   : 0.0000   Mean   : 0.0000  
##  3rd Qu.: 1.4673   3rd Qu.: 0.537   3rd Qu.: 0.6755   3rd Qu.: 0.6299  
##  Max.   : 1.4673   Max.   : 0.537   Max.   : 0.6755   Max.   : 0.6299  
##   no_educaion        no_aparmen       siuaion_fin      aparmen_siuaion  
##  Min.   :-2.6994   Min.   :-1.8516   Min.   :-1.4140   Min.   :-2.1066  
##  1st Qu.: 0.3701   1st Qu.: 0.5396   1st Qu.:-1.0119   1st Qu.:-0.6883  
##  Median : 0.3701   Median : 0.5396   Median : 0.5287   Median : 0.2975  
##  Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000   Mean   : 0.0000  
##  3rd Qu.: 0.3701   3rd Qu.: 0.5396   3rd Qu.: 0.5287   3rd Qu.: 0.2975  
##  Max.   : 0.3701   Max.   : 0.5396   Max.   : 1.5891   Max.   : 3.0706

5 Results

After quantifying the categorical variables through optimal scaling, Principal Component Analysis was performed. The preliminary analysis of the adequacy of the selection of variables indicates that there is a basis for applying PCA.

colnames(data.s)
##  [1] "fla_area"        "car"             "v_colour"        "video_player"   
##  [5] "saelie"          "cd_player"       "compuer"         "inerne"         
##  [9] "washing"         "machine"         "dishwasher"      "microwave"      
## [13] "freezer"         "el"              "no_food_clohes"  "no_reamen"      
## [17] "no_educaion"     "no_aparmen"      "siuaion_fin"     "aparmen_siuaion"

In this paper two approaches are considered: prcomp() and princomp() for PCA. The procedure prcomp() use the singular value decomposition (SVD).

# prcomp() - PCA basic command from stats:
# centering data around 0 (center=TRUE) by shifting the variables
# rescaling variance to one (unit) (scale.=TRUE)
PCA_sondaz <- prcomp(data.s, center=TRUE, scale=TRUE)
PCA_sondaz
## Standard deviations (1, .., p=20):
##  [1] 2.2226057 1.5201938 1.1885940 1.0638010 1.0031870 0.9667459 0.9360685
##  [8] 0.9026622 0.8813330 0.8547610 0.8480405 0.8243927 0.7926269 0.7648995
## [15] 0.7529300 0.7053451 0.6740203 0.6557288 0.5579307 0.4394618
## 
## Rotation (n x k) = (20 x 20):
##                        PC1         PC2         PC3           PC4          PC5
## fla_area         0.0210327 -0.28029291  0.46443292 -8.951332e-03  0.307329627
## car             -0.2812000  0.06478813  0.10813153 -1.378984e-01 -0.067035193
## v_colour        -0.1078562  0.08201130 -0.08133650 -5.047907e-01 -0.094713221
## video_player    -0.2769384  0.22668227  0.02620493 -1.380239e-01 -0.154436355
## saelie          -0.1705138  0.02579958  0.33030848 -1.474442e-01 -0.138505225
## cd_player       -0.3069504  0.17282597 -0.05168192  3.936375e-02 -0.109570045
## compuer         -0.3168397  0.23745612 -0.12533109  2.208387e-01  0.239097517
## inerne          -0.3091436  0.18980458 -0.14672626  3.106617e-01  0.241958643
## washing         -0.2081214  0.06538875  0.02101971 -4.100576e-01  0.377833309
## machine         -0.1081032  0.01034346  0.27335715  3.551096e-01 -0.557769063
## dishwasher      -0.1670237 -0.01730783  0.27067018  3.452405e-01  0.099932535
## microwave       -0.2333310  0.10770587  0.19441407  1.587887e-02  0.062734109
## freezer         -0.1312643 -0.02389469  0.37780561 -2.879348e-01 -0.289577619
## el              -0.2759079  0.27083936 -0.06154688 -5.918334e-02 -0.033266110
## no_food_clohes  -0.2660416 -0.37274999 -0.19824810 -1.972604e-02 -0.048420793
## no_reamen       -0.2755538 -0.29687753 -0.24508435 -3.375987e-02  0.009219708
## no_educaion     -0.1288467 -0.39825078 -0.20285197  8.644942e-05 -0.122628804
## no_aparmen      -0.2178961 -0.38221438 -0.15745850 -5.184980e-02 -0.173176561
## siuaion_fin     -0.2323404 -0.18333434  0.01611853  1.846580e-01  0.001860157
## aparmen_siuaion -0.1320561 -0.28388824  0.34347538  7.195153e-03  0.348027976
##                         PC6          PC7           PC8         PC9         PC10
## fla_area        -0.02177672 -0.005103380  8.573949e-02 -0.16169895  0.001919977
## car              0.32644850 -0.076563484 -2.781732e-02 -0.08297071  0.268774165
## v_colour        -0.70028240  0.004574490 -2.430990e-01 -0.16984226  0.292852351
## video_player     0.01544580  0.021192488  2.052911e-01  0.09425397 -0.300307242
## saelie           0.14371241 -0.676391264  7.304167e-02 -0.41789558  0.015789212
## cd_player        0.04454145  0.074177776  8.367777e-02 -0.01200382 -0.377567826
## compuer          0.04184996  0.018392045 -1.022833e-01 -0.15342601  0.236316732
## inerne          -0.05277122  0.003416087 -1.664257e-01 -0.04257539  0.259167100
## washing         -0.14931749  0.036948566  2.072252e-01  0.13082873 -0.387735159
## machine         -0.37066780  0.200238826  3.231946e-01 -0.11985924 -0.006523110
## dishwasher      -0.31480280 -0.368087785 -4.596148e-01  0.38503049 -0.292962432
## microwave       -0.02724318 -0.018127711  3.860436e-01  0.50264972  0.428197706
## freezer          0.30375598  0.340184293 -5.045772e-01  0.25206668  0.047822744
## el               0.10011224  0.108772742  3.922493e-02 -0.06219302 -0.046775912
## no_food_clohes   0.03368059 -0.034021800 -1.111572e-03  0.02089511 -0.022399076
## no_reamen        0.03546696  0.003485599  4.268592e-03 -0.07313130 -0.140207753
## no_educaion     -0.03916628 -0.168323634  1.016125e-01  0.23047940  0.085168028
## no_aparmen       0.03611721 -0.086679903 -9.548153e-05  0.11241269  0.109584087
## siuaion_fin     -0.01449390  0.299826495 -2.000663e-01 -0.38437590 -0.127040031
## aparmen_siuaion -0.08879989  0.313907359  1.611111e-01 -0.10012941  0.079950880
##                        PC11        PC12        PC13         PC14        PC15
## fla_area         0.59578689  0.26956679 -0.17751585 -0.117686112  0.29891833
## car              0.01206635 -0.19837173  0.49509339  0.094381438  0.44840879
## v_colour         0.02880431  0.16624311  0.04532247 -0.059709227  0.02686918
## video_player     0.04064730  0.36297136  0.07257132 -0.148981966 -0.19196576
## saelie          -0.18827759 -0.03330864 -0.18610932  0.058536788 -0.24532354
## cd_player        0.12314439  0.29117904  0.03432883  0.005321009 -0.11925727
## compuer          0.19239346 -0.08424490 -0.11105140  0.073011986 -0.20744724
## inerne           0.18903586 -0.09758353 -0.14997048  0.092919381 -0.18604133
## washing         -0.02811856 -0.51804270 -0.18225118  0.259041025  0.11240032
## machine          0.17219854 -0.36750323 -0.01579886  0.091550027  0.03038090
## dishwasher      -0.09526121 -0.01502780  0.21693362 -0.057316631  0.12986883
## microwave       -0.30714100  0.15106852 -0.31609117 -0.197444726  0.15616836
## freezer          0.10838654 -0.08894968 -0.24491527  0.095518326 -0.21743605
## el               0.09753180  0.15268795  0.24917209  0.051922086  0.27482974
## no_food_clohes   0.05537781 -0.18142595 -0.01771316 -0.213458994 -0.04930351
## no_reamen        0.08271029 -0.06599411 -0.14473974 -0.334705314  0.02653340
## no_educaion      0.11736886  0.28901047 -0.02274629  0.743491912 -0.01326024
## no_aparmen       0.02714326 -0.09677663  0.13728128 -0.278721879 -0.06428452
## siuaion_fin     -0.52831949  0.18775711 -0.29420710  0.116358164  0.35331445
## aparmen_siuaion -0.24574976  0.05446858  0.46445385  0.053768247 -0.45832031
##                        PC16        PC17         PC18        PC19         PC20
## fla_area         0.05330408 -0.09649605 -0.019275919  0.04346068  0.002576881
## car              0.39170432  0.17788938  0.005876287 -0.09297635  0.029156607
## v_colour         0.04602592  0.08434368 -0.049761848  0.02244782 -0.009938797
## video_player     0.36053172 -0.27685674  0.526419192 -0.07023873  0.005925266
## saelie          -0.15096255  0.00391472 -0.021086903  0.01541977  0.059669942
## cd_player        0.13433822  0.30140422 -0.680533163  0.11749075  0.036015563
## compuer          0.03545689 -0.05088874  0.022822276 -0.02515199 -0.720995823
## inerne           0.10009440 -0.10870669  0.031546632 -0.03066927  0.676447705
## washing          0.03040881 -0.14098867 -0.057761475 -0.02736735  0.002553528
## machine         -0.02221873  0.01808360  0.046909428 -0.04764629 -0.019061929
## dishwasher      -0.04071345  0.03098437  0.054147073 -0.02315631 -0.082797669
## microwave       -0.05290758  0.11880224 -0.083784822  0.03006894 -0.024082605
## freezer         -0.07995603  0.03088850  0.020936940 -0.02083593  0.004392615
## el              -0.76441495 -0.15979857  0.101103406  0.12519997  0.061418442
## no_food_clohes   0.03257162  0.17182423  0.210431545  0.76540415 -0.003324991
## no_reamen       -0.18893474  0.45606199  0.186180003 -0.56966017  0.024617665
## no_educaion     -0.02381444  0.04623275  0.084882692 -0.07533830 -0.040991823
## no_aparmen      -0.01299417 -0.65659558 -0.377365944 -0.17231185 -0.036722598
## siuaion_fin      0.12102183 -0.17084304  0.011478823  0.02055660 -0.018379291
## aparmen_siuaion -0.10380037  0.09103052  0.008896862 -0.04122395  0.033980606
PCA_sondaz$rotation
##                        PC1         PC2         PC3           PC4          PC5
## fla_area         0.0210327 -0.28029291  0.46443292 -8.951332e-03  0.307329627
## car             -0.2812000  0.06478813  0.10813153 -1.378984e-01 -0.067035193
## v_colour        -0.1078562  0.08201130 -0.08133650 -5.047907e-01 -0.094713221
## video_player    -0.2769384  0.22668227  0.02620493 -1.380239e-01 -0.154436355
## saelie          -0.1705138  0.02579958  0.33030848 -1.474442e-01 -0.138505225
## cd_player       -0.3069504  0.17282597 -0.05168192  3.936375e-02 -0.109570045
## compuer         -0.3168397  0.23745612 -0.12533109  2.208387e-01  0.239097517
## inerne          -0.3091436  0.18980458 -0.14672626  3.106617e-01  0.241958643
## washing         -0.2081214  0.06538875  0.02101971 -4.100576e-01  0.377833309
## machine         -0.1081032  0.01034346  0.27335715  3.551096e-01 -0.557769063
## dishwasher      -0.1670237 -0.01730783  0.27067018  3.452405e-01  0.099932535
## microwave       -0.2333310  0.10770587  0.19441407  1.587887e-02  0.062734109
## freezer         -0.1312643 -0.02389469  0.37780561 -2.879348e-01 -0.289577619
## el              -0.2759079  0.27083936 -0.06154688 -5.918334e-02 -0.033266110
## no_food_clohes  -0.2660416 -0.37274999 -0.19824810 -1.972604e-02 -0.048420793
## no_reamen       -0.2755538 -0.29687753 -0.24508435 -3.375987e-02  0.009219708
## no_educaion     -0.1288467 -0.39825078 -0.20285197  8.644942e-05 -0.122628804
## no_aparmen      -0.2178961 -0.38221438 -0.15745850 -5.184980e-02 -0.173176561
## siuaion_fin     -0.2323404 -0.18333434  0.01611853  1.846580e-01  0.001860157
## aparmen_siuaion -0.1320561 -0.28388824  0.34347538  7.195153e-03  0.348027976
##                         PC6          PC7           PC8         PC9         PC10
## fla_area        -0.02177672 -0.005103380  8.573949e-02 -0.16169895  0.001919977
## car              0.32644850 -0.076563484 -2.781732e-02 -0.08297071  0.268774165
## v_colour        -0.70028240  0.004574490 -2.430990e-01 -0.16984226  0.292852351
## video_player     0.01544580  0.021192488  2.052911e-01  0.09425397 -0.300307242
## saelie           0.14371241 -0.676391264  7.304167e-02 -0.41789558  0.015789212
## cd_player        0.04454145  0.074177776  8.367777e-02 -0.01200382 -0.377567826
## compuer          0.04184996  0.018392045 -1.022833e-01 -0.15342601  0.236316732
## inerne          -0.05277122  0.003416087 -1.664257e-01 -0.04257539  0.259167100
## washing         -0.14931749  0.036948566  2.072252e-01  0.13082873 -0.387735159
## machine         -0.37066780  0.200238826  3.231946e-01 -0.11985924 -0.006523110
## dishwasher      -0.31480280 -0.368087785 -4.596148e-01  0.38503049 -0.292962432
## microwave       -0.02724318 -0.018127711  3.860436e-01  0.50264972  0.428197706
## freezer          0.30375598  0.340184293 -5.045772e-01  0.25206668  0.047822744
## el               0.10011224  0.108772742  3.922493e-02 -0.06219302 -0.046775912
## no_food_clohes   0.03368059 -0.034021800 -1.111572e-03  0.02089511 -0.022399076
## no_reamen        0.03546696  0.003485599  4.268592e-03 -0.07313130 -0.140207753
## no_educaion     -0.03916628 -0.168323634  1.016125e-01  0.23047940  0.085168028
## no_aparmen       0.03611721 -0.086679903 -9.548153e-05  0.11241269  0.109584087
## siuaion_fin     -0.01449390  0.299826495 -2.000663e-01 -0.38437590 -0.127040031
## aparmen_siuaion -0.08879989  0.313907359  1.611111e-01 -0.10012941  0.079950880
##                        PC11        PC12        PC13         PC14        PC15
## fla_area         0.59578689  0.26956679 -0.17751585 -0.117686112  0.29891833
## car              0.01206635 -0.19837173  0.49509339  0.094381438  0.44840879
## v_colour         0.02880431  0.16624311  0.04532247 -0.059709227  0.02686918
## video_player     0.04064730  0.36297136  0.07257132 -0.148981966 -0.19196576
## saelie          -0.18827759 -0.03330864 -0.18610932  0.058536788 -0.24532354
## cd_player        0.12314439  0.29117904  0.03432883  0.005321009 -0.11925727
## compuer          0.19239346 -0.08424490 -0.11105140  0.073011986 -0.20744724
## inerne           0.18903586 -0.09758353 -0.14997048  0.092919381 -0.18604133
## washing         -0.02811856 -0.51804270 -0.18225118  0.259041025  0.11240032
## machine          0.17219854 -0.36750323 -0.01579886  0.091550027  0.03038090
## dishwasher      -0.09526121 -0.01502780  0.21693362 -0.057316631  0.12986883
## microwave       -0.30714100  0.15106852 -0.31609117 -0.197444726  0.15616836
## freezer          0.10838654 -0.08894968 -0.24491527  0.095518326 -0.21743605
## el               0.09753180  0.15268795  0.24917209  0.051922086  0.27482974
## no_food_clohes   0.05537781 -0.18142595 -0.01771316 -0.213458994 -0.04930351
## no_reamen        0.08271029 -0.06599411 -0.14473974 -0.334705314  0.02653340
## no_educaion      0.11736886  0.28901047 -0.02274629  0.743491912 -0.01326024
## no_aparmen       0.02714326 -0.09677663  0.13728128 -0.278721879 -0.06428452
## siuaion_fin     -0.52831949  0.18775711 -0.29420710  0.116358164  0.35331445
## aparmen_siuaion -0.24574976  0.05446858  0.46445385  0.053768247 -0.45832031
##                        PC16        PC17         PC18        PC19         PC20
## fla_area         0.05330408 -0.09649605 -0.019275919  0.04346068  0.002576881
## car              0.39170432  0.17788938  0.005876287 -0.09297635  0.029156607
## v_colour         0.04602592  0.08434368 -0.049761848  0.02244782 -0.009938797
## video_player     0.36053172 -0.27685674  0.526419192 -0.07023873  0.005925266
## saelie          -0.15096255  0.00391472 -0.021086903  0.01541977  0.059669942
## cd_player        0.13433822  0.30140422 -0.680533163  0.11749075  0.036015563
## compuer          0.03545689 -0.05088874  0.022822276 -0.02515199 -0.720995823
## inerne           0.10009440 -0.10870669  0.031546632 -0.03066927  0.676447705
## washing          0.03040881 -0.14098867 -0.057761475 -0.02736735  0.002553528
## machine         -0.02221873  0.01808360  0.046909428 -0.04764629 -0.019061929
## dishwasher      -0.04071345  0.03098437  0.054147073 -0.02315631 -0.082797669
## microwave       -0.05290758  0.11880224 -0.083784822  0.03006894 -0.024082605
## freezer         -0.07995603  0.03088850  0.020936940 -0.02083593  0.004392615
## el              -0.76441495 -0.15979857  0.101103406  0.12519997  0.061418442
## no_food_clohes   0.03257162  0.17182423  0.210431545  0.76540415 -0.003324991
## no_reamen       -0.18893474  0.45606199  0.186180003 -0.56966017  0.024617665
## no_educaion     -0.02381444  0.04623275  0.084882692 -0.07533830 -0.040991823
## no_aparmen      -0.01299417 -0.65659558 -0.377365944 -0.17231185 -0.036722598
## siuaion_fin      0.12102183 -0.17084304  0.011478823  0.02055660 -0.018379291
## aparmen_siuaion -0.10380037  0.09103052  0.008896862 -0.04122395  0.033980606
biplot(PCA_sondaz, scale=0)

summary(PCA_sondaz)
## Importance of components:
##                          PC1    PC2     PC3     PC4     PC5     PC6     PC7
## Standard deviation     2.223 1.5202 1.18859 1.06380 1.00319 0.96675 0.93607
## Proportion of Variance 0.247 0.1155 0.07064 0.05658 0.05032 0.04673 0.04381
## Cumulative Proportion  0.247 0.3625 0.43319 0.48977 0.54009 0.58682 0.63063
##                            PC8     PC9    PC10    PC11    PC12    PC13    PC14
## Standard deviation     0.90266 0.88133 0.85476 0.84804 0.82439 0.79263 0.76490
## Proportion of Variance 0.04074 0.03884 0.03653 0.03596 0.03398 0.03141 0.02925
## Cumulative Proportion  0.67137 0.71021 0.74674 0.78270 0.81668 0.84809 0.87734
##                           PC15    PC16    PC17   PC18    PC19    PC20
## Standard deviation     0.75293 0.70535 0.67402 0.6557 0.55793 0.43946
## Proportion of Variance 0.02835 0.02488 0.02272 0.0215 0.01556 0.00966
## Cumulative Proportion  0.90569 0.93057 0.95328 0.9748 0.99034 1.00000

This table presents the eigenvalues of successive components, the percentage of the total variance explained by the successive components and the cumulative percentage of explained variance. Eigenvalues greater than 1 allow the identification of five principal components. Using the scree test to select the number of factors, it makes sense to leave 3 components (the scree plot shows that there is a slight decrease in eigenvalues to the right of the third component). A sensible interpretation of the main components as dimensions of poverty is possible in the case of 3 components. They account for 43.3% of the total variance. Therefore, the principal components analysis for 3 components was performed.

The procedure princomp() uses the spectral decomposition approach.

PCA_sondaz2<-princomp(data.s) 
loadings(PCA_sondaz2)
## 
## Loadings:
##                 Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7 Comp.8 Comp.9
## fla_area                0.280  0.464         0.307                       0.162
## car             -0.281         0.108  0.138        -0.326                     
## v_colour        -0.108                0.505         0.700        -0.243  0.170
## video_player    -0.277 -0.227         0.138 -0.154                0.205       
## saelie          -0.171         0.330  0.147 -0.139 -0.144  0.676         0.418
## cd_player       -0.307 -0.173               -0.110                            
## compuer         -0.317 -0.237 -0.125 -0.221  0.239               -0.102  0.153
## inerne          -0.309 -0.190 -0.147 -0.311  0.242               -0.166       
## washing         -0.208                0.410  0.378  0.149         0.207 -0.131
## machine         -0.108         0.273 -0.355 -0.558  0.371 -0.200  0.323  0.120
## dishwasher      -0.167         0.271 -0.345         0.315  0.368 -0.460 -0.385
## microwave       -0.233 -0.108  0.194                              0.386 -0.503
## freezer         -0.131         0.378  0.288 -0.290 -0.304 -0.340 -0.505 -0.252
## el              -0.276 -0.271                      -0.100 -0.109              
## no_food_clohes  -0.266  0.373 -0.198                                          
## no_reamen       -0.276  0.297 -0.245                                          
## no_educaion     -0.129  0.398 -0.203        -0.123         0.168  0.102 -0.230
## no_aparmen      -0.218  0.382 -0.157        -0.173                      -0.112
## siuaion_fin     -0.232  0.183        -0.185               -0.300 -0.200  0.384
## aparmen_siuaion -0.132  0.284  0.343         0.348        -0.314  0.161  0.100
##                 Comp.10 Comp.11 Comp.12 Comp.13 Comp.14 Comp.15 Comp.16 Comp.17
## fla_area                 0.596   0.270   0.178   0.118   0.299                 
## car              0.269          -0.198  -0.495           0.448   0.392  -0.178 
## v_colour         0.293           0.166                                         
## video_player    -0.300           0.363           0.149  -0.192   0.361   0.277 
## saelie                  -0.188           0.186          -0.245  -0.151         
## cd_player       -0.378   0.123   0.291                  -0.119   0.134  -0.301 
## compuer          0.236   0.192           0.111          -0.207                 
## inerne           0.259   0.189           0.150          -0.186   0.100   0.109 
## washing         -0.388          -0.518   0.182  -0.259   0.112           0.141 
## machine                  0.172  -0.368                                         
## dishwasher      -0.293                  -0.217           0.130                 
## microwave        0.428  -0.307   0.151   0.316   0.197   0.156          -0.119 
## freezer                  0.108           0.245          -0.217                 
## el                               0.153  -0.249           0.275  -0.764   0.160 
## no_food_clohes                  -0.181           0.213                  -0.172 
## no_reamen       -0.140                   0.145   0.335          -0.189  -0.456 
## no_educaion              0.117   0.289          -0.743                         
## no_aparmen       0.110                  -0.137   0.279                   0.657 
## siuaion_fin     -0.127  -0.528   0.188   0.294  -0.116   0.353   0.121   0.171 
## aparmen_siuaion         -0.246          -0.464          -0.458  -0.104         
##                 Comp.18 Comp.19 Comp.20
## fla_area                               
## car                                    
## v_colour                               
## video_player    -0.526                 
## saelie                                 
## cd_player        0.681   0.117         
## compuer                         -0.721 
## inerne                           0.676 
## washing                                
## machine                                
## dishwasher                             
## microwave                              
## freezer                                
## el              -0.101   0.125         
## no_food_clohes  -0.210   0.765         
## no_reamen       -0.186  -0.570         
## no_educaion                            
## no_aparmen       0.377  -0.172         
## siuaion_fin                            
## aparmen_siuaion                        
## 
##                Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7 Comp.8 Comp.9
## SS loadings      1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
## Proportion Var   0.05   0.05   0.05   0.05   0.05   0.05   0.05   0.05   0.05
## Cumulative Var   0.05   0.10   0.15   0.20   0.25   0.30   0.35   0.40   0.45
##                Comp.10 Comp.11 Comp.12 Comp.13 Comp.14 Comp.15 Comp.16 Comp.17
## SS loadings       1.00    1.00    1.00    1.00    1.00    1.00    1.00    1.00
## Proportion Var    0.05    0.05    0.05    0.05    0.05    0.05    0.05    0.05
## Cumulative Var    0.50    0.55    0.60    0.65    0.70    0.75    0.80    0.85
##                Comp.18 Comp.19 Comp.20
## SS loadings       1.00    1.00    1.00
## Proportion Var    0.05    0.05    0.05
## Cumulative Var    0.90    0.95    1.00

5.1 Visualization and Interpretation

#install.packages("factoextra")
library(factoextra)
## Welcome! Want to learn more? See two factoextra-related books at https://goo.gl/ve3WBa

5.1.1 Correlation circle

The correlation between the variable and the main component (PC) is used as the coordinates of the variable on the PC.

plot(PCA_sondaz2)

fviz_pca_var(PCA_sondaz, col.var="steelblue")

This part of analysis present the variable correlation plots. Positively correlated variables are grouped together. Otherwise negatively correlated variables are positioned on opposite sides of the plot origin (opposed quadrants).

In sum, two approarch are given the similar results.

5.1.2 Visusalisation of quality

fviz_eig(PCA_sondaz, addlabels = TRUE) 

In order to verify the number of major components, the eigenvalues should be analyzed. Based on the graph above and the table below, we choose the third principal component.

eig.val<-get_eigenvalue(PCA_sondaz)
eig.val
##        eigenvalue variance.percent cumulative.variance.percent
## Dim.1   4.9399762       24.6998810                    24.69988
## Dim.2   2.3109893       11.5549467                    36.25483
## Dim.3   1.4127558        7.0637790                    43.31861
## Dim.4   1.1316726        5.6583632                    48.97697
## Dim.5   1.0063842        5.0319209                    54.00889
## Dim.6   0.9345976        4.6729878                    58.68188
## Dim.7   0.8762241        4.3811207                    63.06300
## Dim.8   0.8147991        4.0739953                    67.13699
## Dim.9   0.7767478        3.8837390                    71.02073
## Dim.10  0.7306164        3.6530821                    74.67382
## Dim.11  0.7191726        3.5958631                    78.26968
## Dim.12  0.6796234        3.3981170                    81.66780
## Dim.13  0.6282574        3.1412870                    84.80908
## Dim.14  0.5850712        2.9253561                    87.73444
## Dim.15  0.5669035        2.8345176                    90.56896
## Dim.16  0.4975117        2.4875584                    93.05651
## Dim.17  0.4543034        2.2715170                    95.32803
## Dim.18  0.4299803        2.1499015                    97.47793
## Dim.19  0.3112867        1.5564335                    99.03437
## Dim.20  0.1931266        0.9656332                   100.00000
a<-summary(PCA_sondaz)
plot(a$importance[3,],type="l") 

The most significant variables are analyzed that constitute PC1.

loading_scores_PC_1<-PCA_sondaz$rotation[,1]
fac_scores_PC_1<-abs(loading_scores_PC_1)
fac_scores_PC_1_ranked<-names(sort(fac_scores_PC_1, decreasing=T))
PCA_sondaz$rotation[fac_scores_PC_1_ranked, 1]
##         compuer          inerne       cd_player             car    video_player 
##      -0.3168397      -0.3091436      -0.3069504      -0.2812000      -0.2769384 
##              el       no_reamen  no_food_clohes       microwave     siuaion_fin 
##      -0.2759079      -0.2755538      -0.2660416      -0.2333310      -0.2323404 
##      no_aparmen         washing          saelie      dishwasher aparmen_siuaion 
##      -0.2178961      -0.2081214      -0.1705138      -0.1670237      -0.1320561 
##         freezer     no_educaion         machine        v_colour        fla_area 
##      -0.1312643      -0.1288467      -0.1081032      -0.1078562       0.0210327
loading_scores_PC_2<-PCA_sondaz$rotation[,2]
fac_scores_PC_2<-abs(loading_scores_PC_2)
fac_scores_PC_2_ranked<-names(sort(fac_scores_PC_2, decreasing=T))
PCA_sondaz$rotation[fac_scores_PC_2_ranked, 2]
##     no_educaion      no_aparmen  no_food_clohes       no_reamen aparmen_siuaion 
##     -0.39825078     -0.38221438     -0.37274999     -0.29687753     -0.28388824 
##        fla_area              el         compuer    video_player          inerne 
##     -0.28029291      0.27083936      0.23745612      0.22668227      0.18980458 
##     siuaion_fin       cd_player       microwave        v_colour         washing 
##     -0.18333434      0.17282597      0.10770587      0.08201130      0.06538875 
##             car          saelie         freezer      dishwasher         machine 
##      0.06478813      0.02579958     -0.02389469     -0.01730783      0.01034346
loading_scores_PC_3<-PCA_sondaz$rotation[,3]
fac_scores_PC_3<-abs(loading_scores_PC_2)
fac_scores_PC_3_ranked<-names(sort(fac_scores_PC_3, decreasing=T))
PCA_sondaz$rotation[fac_scores_PC_3_ranked, 3]
##     no_educaion      no_aparmen  no_food_clohes       no_reamen aparmen_siuaion 
##     -0.20285197     -0.15745850     -0.19824810     -0.24508435      0.34347538 
##        fla_area              el         compuer    video_player          inerne 
##      0.46443292     -0.06154688     -0.12533109      0.02620493     -0.14672626 
##     siuaion_fin       cd_player       microwave        v_colour         washing 
##      0.01611853     -0.05168192      0.19441407     -0.08133650      0.02101971 
##             car          saelie         freezer      dishwasher         machine 
##      0.10813153      0.33030848      0.37780561      0.27067018      0.27335715

5.1.3 Graph of individuals

The above analysis provides a list of matrices containing all scores for persons (coordinates, correlations between persons and axes, cosine squared and contributions).

ind<-get_pca_ind(PCA_sondaz)
print(ind)
## Principal Component Analysis Results for individuals
##  ===================================================
##   Name       Description                       
## 1 "$coord"   "Coordinates for the individuals" 
## 2 "$cos2"    "Cos2 for the individuals"        
## 3 "$contrib" "contributions of the individuals"

The coordinates of individuals is below:

head(ind$coord)
##       Dim.1      Dim.2      Dim.3      Dim.4      Dim.5      Dim.6      Dim.7
## 1  2.330862 -2.2128044 -1.0617138 -0.5363029  0.3414520 -0.8215527 -0.2756493
## 2  2.533416 -1.7254566 -1.6713366 -0.5460945 -0.2502165 -0.6796196 -0.7642926
## 3  2.596719 -1.8229552 -1.4634524 -0.5551447 -0.1567322 -0.6628280 -0.8825546
## 4  2.325629 -2.4984437  0.5478922 -0.2179283 -1.6419308  0.5931932 -1.1227701
## 5  1.487973 -2.0428552  0.3475797 -0.3265893 -1.2627780  1.1575150  0.4421925
## 6 -3.101770  0.2826362  1.7220626  1.9671891 -1.0041789 -1.9032591 -1.9347156
##        Dim.8       Dim.9     Dim.10      Dim.11     Dim.12      Dim.13
## 1  0.1324714  0.39434590 -0.1631445 -0.04821283 -1.1876731 -0.02812483
## 2 -0.1324122  0.57625748 -0.2881133  0.23996169 -1.3155898 -0.72401231
## 3 -0.1297029  0.49677657 -0.3159236  0.75721732 -1.1420330 -1.02095878
## 4 -1.4022466 -0.42111562  1.1645062  0.05375411  0.2253103 -0.45397101
## 5 -1.4400269  0.01214875  1.5600895  1.28910456  0.5227832  1.37092907
## 6  0.8644046  0.67212984 -0.2271571  1.05308094 -1.1095689  0.73838222
##       Dim.14      Dim.15     Dim.16    Dim.17      Dim.18      Dim.19
## 1 -0.3123004 -0.71577795  0.1161038 0.3793659 -0.08269062 -0.12289320
## 2 -0.3773709 -0.04881389  0.2694533 0.2528153 -0.09348909 -0.06554570
## 3 -0.4814523  0.33301217  0.3455994 0.1503365 -0.11056958 -0.01930835
## 4 -0.8131632 -1.96314136 -0.4584987 0.8561781  0.08783230 -0.03643922
## 5 -0.7382323  0.41339559 -1.1267882 0.7296678  0.36921875  0.08516950
## 6 -0.2006754 -0.04394799 -0.2219509 0.3925125  0.12556805 -0.14510895
##        Dim.20
## 1 -0.01671272
## 2 -0.07010760
## 3 -0.08066389
## 4  0.11475997
## 5  0.19402104
## 6 -0.07133706

The contributions of individuals to PC:

head(ind$contrib) 
##        Dim.1       Dim.2       Dim.3       Dim.4       Dim.5      Dim.6
## 1 0.09472752 0.182497062 0.068725141 0.021891086 0.009978456 0.06220338
## 2 0.11190663 0.110962936 0.170305443 0.022697735 0.005358409 0.04256718
## 3 0.11756902 0.123857358 0.130574356 0.023456296 0.002102423 0.04048972
## 4 0.09430263 0.232653164 0.018301679 0.003614715 0.230735102 0.03242915
## 5 0.03860404 0.155541036 0.007365622 0.008118033 0.136476530 0.12347992
## 6 0.16774983 0.002977318 0.180800051 0.294536549 0.086303049 0.33384046
##         Dim.7       Dim.8        Dim.9      Dim.10       Dim.11      Dim.12
## 1 0.007469064 0.001855076 1.724417e-02 0.003137784 0.0002783941 0.178769433
## 2 0.057421153 0.001853418 3.682315e-02 0.009785996 0.0068963368 0.219351420
## 3 0.076565959 0.001778348 2.736591e-02 0.011766371 0.0686713706 0.165293866
## 4 0.123917950 0.207857684 1.966484e-02 0.159868145 0.0003460653 0.006433711
## 5 0.019220974 0.219209039 1.636631e-05 0.286930955 0.1990265102 0.034637190
## 6 0.367948310 0.078986236 5.009497e-02 0.006083184 0.1328183683 0.156029966
##         Dim.13      Dim.14       Dim.15      Dim.16      Dim.17      Dim.18
## 1 0.0001084451 0.014358333 0.0778422295 0.002333765 0.027285904 0.001369720
## 2 0.0718657691 0.020965050 0.0003620307 0.012569890 0.012117936 0.001750818
## 3 0.1429047246 0.034124441 0.0168491827 0.020678091 0.004284999 0.002449010
## 4 0.0282544206 0.097345179 0.5855470250 0.036394912 0.138979257 0.001545353
## 5 0.2576677945 0.080231534 0.0259651193 0.219810844 0.100942064 0.027307800
## 6 0.0747468053 0.005928535 0.0002934517 0.008528608 0.029209813 0.003158476
##         Dim.19       Dim.20
## 1 0.0041789093 0.0001245718
## 2 0.0011887640 0.0021920769
## 3 0.0001031567 0.0029019102
## 4 0.0003674052 0.0058736282
## 5 0.0020071297 0.0167889392
## 6 0.0058263368 0.0022696348

To visualize the total contributions of individual variables to PC1, PC2 and PC3:

library(gridExtra)
var<-get_pca_var(PCA_sondaz)
fviz_contrib(PCA_sondaz, "var", axes=1:3) 

5.2 Rotated PCA

In order to obtain the simplest possible structure a rotation should be made. This is a way of maximizing high loads and minimizing light loads.

There are two types of rotation methods, orthogonal and oblique. In orthogonal rotation, the factors after rotation will remain uncorrelated, while in oblique rotation, the factors resulting from the rotation will be correlated.

The most common orthogonal method is called varimax rotation.

library(psych)
## 
## Attaching package: 'psych'
## The following objects are masked from 'package:ggplot2':
## 
##     %+%, alpha
PCA_sondaz3<-principal(data, nfactors=3, rotate="varimax")
PCA_sondaz3
## Principal Components Analysis
## Call: principal(r = data, nfactors = 3, rotate = "varimax")
## Standardized loadings (pattern matrix) based upon correlation matrix
##                   RC1   RC2   RC3    h2   u2 com
## fla_area        -0.41  0.13  0.55 0.488 0.51 2.0
## car              0.52  0.18  0.34 0.417 0.58 2.0
## v_colour         0.28  0.05 -0.02 0.082 0.92 1.1
## video_player     0.68  0.01  0.21 0.499 0.50 1.2
## saelie           0.23  0.02  0.49 0.299 0.70 1.4
## cd_player        0.70  0.14  0.16 0.538 0.46 1.2
## compuer          0.79  0.11  0.07 0.648 0.35 1.1
## inerne           0.75  0.17  0.05 0.586 0.41 1.1
## washing          0.42  0.14  0.18 0.224 0.78 1.6
## machine          0.12 -0.01  0.38 0.164 0.84 1.2
## dishwasher       0.20  0.09  0.44 0.242 0.76 1.5
## microwave        0.45  0.04  0.38 0.349 0.65 2.0
## freezer          0.11  0.02  0.53 0.288 0.71 1.1
## el               0.74  0.00  0.10 0.551 0.45 1.0
## no_food_clohes   0.19  0.82  0.10 0.726 0.27 1.1
## no_reamen        0.29  0.76  0.04 0.664 0.34 1.3
## no_educaion     -0.07  0.71 -0.01 0.507 0.49 1.0
## no_aparmen       0.09  0.77  0.11 0.607 0.39 1.1
## siuaion_fin      0.24  0.47  0.26 0.345 0.66 2.1
## aparmen_siuaion -0.11  0.35  0.55 0.439 0.56 1.8
## 
##                        RC1  RC2  RC3
## SS loadings           3.89 2.84 1.94
## Proportion Var        0.19 0.14 0.10
## Cumulative Var        0.19 0.34 0.43
## Proportion Explained  0.45 0.33 0.22
## Cumulative Proportion 0.45 0.78 1.00
## 
## Mean item complexity =  1.4
## Test of the hypothesis that 3 components are sufficient.
## 
## The root mean square of the residuals (RMSR) is  0.06 
##  with the empirical chi square  1757.88  with prob <  2.1e-281 
## 
## Fit based upon off diagonal values = 0.93
summary(PCA_sondaz3)
## 
## Factor analysis with Call: principal(r = data, nfactors = 3, rotate = "varimax")
## 
## Test of the hypothesis that 3 factors are sufficient.
## The degrees of freedom for the model is 133  and the objective function was  1.06 
## The number of observations was  1161  with Chi Square =  1216.34  with prob <  2.8e-174 
## 
## The root mean square of the residuals (RMSA) is  0.06
print(loadings(PCA_sondaz3), digits=3, cutoff=0.4, sort=TRUE)
## 
## Loadings:
##                 RC1    RC2    RC3   
## car              0.519              
## video_player     0.675              
## cd_player        0.701              
## compuer          0.795              
## inerne           0.745              
## el               0.736              
## no_food_clohes          0.825       
## no_reamen               0.762       
## no_educaion             0.708       
## no_aparmen              0.767       
## fla_area        -0.406         0.554
## freezer                        0.526
## aparmen_siuaion                0.553
## v_colour                            
## saelie                         0.495
## washing          0.415              
## machine                             
## dishwasher                     0.438
## microwave        0.450              
## siuaion_fin             0.470       
## 
##                  RC1   RC2   RC3
## SS loadings    3.888 2.835 1.940
## Proportion Var 0.194 0.142 0.097
## Cumulative Var 0.194 0.336 0.433

On the basis of the obtained result, it should be noted that after applying the varimax rotation, the charges of the components are very clear.

diagram(PCA_sondaz3)

This above table presents the factor loadings after orthogonal rotation (Varimax), which allows for the interpretation of individual components as subsequent dimensions of poverty. The variables were grouped in such a way as to assign them to the appropriate components (the highest values of loads for each variable were marked).

Ultimately, the next dimensions can be interpreted as follows: the first dimension - “endowment with durable goods”, the second - “livelihood”, and the third - “housing situation”.

The first dimension of poverty relates to the scarcity in terms of equipping a home with durable goods. This dimension consists of 9 variables that determine the possession of such goods as: a computer and related Internet access, a mobile phone, a CD player, a video player, a car, a microwave oven, an automatic washing machine, and a color TV set. These goods are now owned by the vast majority of households, so their forced absence constitutes a significant type of exclusion.

The second poverty dimension includes 5 variables that relate to the ability to meet basic needs and the general financial situation. This dimension consists of variables determining whether it happened that there was a shortage of money for food and clothing, housing, treatment, doctor, education, and a variable describing the overall level of satisfaction with the financial situation. This dimension defines the basic standard of living because a lack of resources for food, housing and other basic expenses can be considered a serious indicator of poverty.

The third dimension of poverty determines the standard of housing. The elements included in this dimension are the living area per person, general satisfaction with the housing situation, and the possession of other less common durable goods such as a dishwasher, separate freezer or washer / dryer or separate dryer. This dimension is not as important an indicator of poverty as the other two, but it does refer to an important element of the overall standard of living, namely the housing situation.

5.3 Quality measures

5.3.1 SCREE PLOTS

The explained variance with consecutive principal components (PC) can be verified.

fviz_eig(PCA_sondaz)

5.3.2 Analisys of the variables used

library(maptools)
## Loading required package: sp
## Checking rgeos availability: TRUE
plot(PCA_sondaz3$complexity)

plot(PCA_sondaz3$complexity, pch=".", xlim=c(-20, 110), main="Factors complexity", sub="Number of variables consists of component factor", xlab=" ", ylab="complexity")
pointLabel(PCA_sondaz3$complexity, labels=names(PCA_sondaz3$complexity), cex=0.8) 

plot(PCA_sondaz3$uniqueness)

plot(PCA_sondaz3$uniqueness, pch=".", xlim=c(-20, 110), main="Uniqueness of factors", sub="Percentage of variance", xlab=" ", ylab="complexity")
pointLabel(PCA_sondaz3$uniqueness, labels=names(PCA_sondaz3$uniqueness), cex=0.8)

plot(PCA_sondaz3$complexity, PCA_sondaz3$uniqueness)

plot(PCA_sondaz3$complexity, PCA_sondaz3$uniqueness, xlim=c(0, 4))
pointLabel(PCA_sondaz3$complexity, PCA_sondaz3$uniqueness, labels=names(PCA_sondaz3$uniqueness), cex=0.8)
abline(h=c(0.38, 0.75), lty=3, col=2)
abline(v=c(1.8), lty=3, col=2)

set<-data.frame(complex=PCA_sondaz3$complexity, unique=PCA_sondaz3$uniqueness)
set.worst<-set[set$complex>1.8 & set$unique>0.78,]
set.worst
## [1] complex unique 
## <0 rows> (or 0-length row.names)

Based on the analysis there are no “Worst variables” which are problematic in analysis.

After defining the poverty dimensions, it is possible to proceed to the assessment of the level of poverty of individuals in subsequent dimensions. The method of defining the variables allows for the interpretation of the values of individual principal components for each unit as its individual indicator of the degree of deficiency in a given dimension (the lower the value of the indicator, the more poor in this dimension a person may be). Comparing the set of poor people in the context of a given dimension with the set of poor people in the context of income will allow to verify the research hypothesis. If these sets overlap it will mean that income can replace multidimensional measures in detecting poor people. However, if these collections differ significantly, the income may be considered insufficient to correctly identify the poor. The value of 60% of the median was adopted as the income poverty line income in the study population. In this case, 20.5% of individuals are counted among the poor. In the case of the designated dimensions, the poverty line was set in such a way that the group of poor people was the same percentage as in the case of income poverty, which would allow for comparison.

Data on the percentage of people in the population of poor people in terms of income, who are also below the poverty line in a given dimension (DIM 1: 15.5%; DIM 2:37.39%; DIM 3: 28.99%). In all dimensions, these values are less than 40% with the highest value for the second dimension. This means that income cannot replace multivariate analysis in identifying poverty. However, it identifies poor people to a slightly better extent in terms of their ability to meet their basic needs (the second poverty dimension).

Therefore, in the future, it is interesting to investigate what characteristics of people, among those above the income poverty line, contribute to the greater likelihood of living in poverty in the context of each poverty dimension.

6 Conclusion

The aim of the above study was to verify the hypothesis that in the case of Poland, the multidimensional analysis of poverty cannot be replaced by a measure based solely on income, without significant differences in the identification of poor people. The study was based on the data contained in the Social Diagnosis study. The multidimensional analysis with the use of principal components analysis, after optimal scaling of categorical variables, allowed to distinguish three main dimensions of poverty.

On the basis of comparing the set of poor people in each poverty dimension, and the set of poor people in terms of income, it can be concluded that these sets do not overlap to a large extent. This means that the classification using only the poverty income index is not sufficient to properly identify the poor, which means that there are no grounds for rejecting the hypothesis.

7 Bibliography

Coromaldi M., Zoli M. (2007), “A Multidimensional Poverty Analysis.Evidence from Italian Data”

Dekkers G. (2003), Financial and multidimensional poverty in european countries: can the former be used as a proxy of the latter?

Siani J. (2015), “A Multidimensional Analysis of Poverty using the Fuzzy Set Approach. Evidence from Cameroonian data,” Economics Bulletin, AccessEcon, vol. 35(3), pages 2012-2025.