PANEL DATA MODEL ANALYSIS

Sys.setenv(LANG = "en")
options(scipen=999)

library(readr)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(plm)
## 
## Attaching package: 'plm'
## The following objects are masked from 'package:dplyr':
## 
##     between, lag, lead
library(stargazer)
## 
## Please cite as:
##  Hlavac, Marek (2022). stargazer: Well-Formatted Regression and Summary Statistics Tables.
##  R package version 5.2.3. https://CRAN.R-project.org/package=stargazer
library(Formula)
library(corrplot)
## corrplot 0.92 loaded
library(lmtest)
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric

Dataset

The dataset used in this analysis was taken from

## Rows: 1155 Columns: 15
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr  (1): economy
## dbl (14): year, id, instututions, human, infra, markets, business, knowledge...
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

Estimating fixed panel data model

fixed <-plm(gdp1~institutions+human+infra+markets+business+innovation+gni+incom_level, data=data, index=c("economy", "year"), model="within")
summary(fixed)
## Oneway (individual) effect Within Model
## 
## Call:
## plm(formula = gdp1 ~ institutions + human + infra + markets + 
##     business + innovation + gni + incom_level, data = data, model = "within", 
##     index = c("economy", "year"))
## 
## Balanced Panel: n = 105, T = 11, N = 1155
## 
## Residuals:
##       Min.    1st Qu.     Median    3rd Qu.       Max. 
## -12095.446   -690.946    -22.087    740.597  17831.202 
## 
## Coefficients:
##                Estimate Std. Error t-value              Pr(>|t|)    
## institutions  47.721435  15.921750  2.9972              0.002789 ** 
## human         21.403960  15.103371  1.4172              0.156734    
## infra        174.428241   9.934317 17.5582 < 0.00000000000000022 ***
## markets      -65.002055  13.352609 -4.8681           0.000001301 ***
## business     -14.606503  13.839193 -1.0554              0.291467    
## innovation   -10.722508  30.793291 -0.3482              0.727753    
## gni            0.460385   0.020265 22.7182 < 0.00000000000000022 ***
## incom_level  225.623268 276.567160  0.8158              0.414801    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Total Sum of Squares:    6389800000
## Residual Sum of Squares: 3310200000
## R-Squared:      0.48195
## Adj. R-Squared: 0.42627
## F-statistic: 121.175 on 8 and 1042 DF, p-value: < 0.000000000000000222

This output presents the results of a fixed effects panel data model estimated using the plm function in R. The model examines the relationship between various independent variables and the dependent variable gdp1 (Gross Domestic Product) for 105 countries over 11 years (from the balanced panel with n = 105, T = 11, N = 1155). The model assumes that the individual-specific effects are fixed and controlled for using within transformation.

The coefficients table presents the estimated coefficients of the independent variables and their corresponding t-values and p-values. The coefficients indicate the average change in gdp1 for a one-unit increase in the respective independent variable, holding all other variables constant.

From the result above, the significant variables are Institution, infra, markets and gni. While the insignificant variables are human, business, innovation and incom_level.

The p-value of the F-test is less than 0.05, indicating that the overall model is statistically significant. The R-squared value of the model is 0.48195, which means that the model explains 48.2% of the variation in gdp1.

Based on the above results, we can conclude that institutions, infrastructure and gni have positive impacts on gdp1, whereas markets variable has a negative impact on gdp1.

Estimate individual effects

fixef(fixed)
##                           Albania                           Algeria 
##                           3339.16                           2662.18 
##                         Argentina                           Armenia 
##                           9835.09                           3530.30 
##                         Australia                           Austria 
##                          10457.68                          19649.33 
##                        Azerbaijan                        Bangladesh 
##                           5645.79                          -1100.12 
##                           Belgium  Bolivia (Plurinational State of) 
##                          18202.81                           2285.83 
##            Bosnia and Herzegovina                          Botswana 
##                           4560.85                           5357.26 
##                            Brazil                          Bulgaria 
##                           2778.76                           8248.58 
##                      Burkina Faso                          Cambodia 
##                          -2723.53                           -139.89 
##                          Cameroon                            Canada 
##                          -1363.02                          15390.35 
##                             Chile                             China 
##                           8648.04                           1521.40 
##                          Colombia                        Costa Rica 
##                           2347.61                           6385.88 
##                      Cote dIvoire                           Croatia 
##                           -799.09                          10220.26 
##                            Cyprus                    Czech Republic 
##                          15915.58                          17634.06 
##                           Denmark                           Ecuador 
##                          14621.98                           2456.40 
##                             Egypt                       El Salvador 
##                           3467.82                            800.68 
##                           Estonia                           Finland 
##                          12446.66                          12517.21 
##                            France                           Georgia 
##                          13746.04                           4249.98 
##                           Germany                            Greece 
##                          19190.24                          10008.79 
##                         Guatemala                          Honduras 
##                           1977.24                            -15.19 
##                 Hong Kong (China)                           Hungary 
##                          26177.89                          12308.24 
##                           Iceland                             India 
##                          16623.91                           -833.67 
##                         Indonesia                           Ireland 
##                           2909.64                          37746.35 
##                            Israel                             Italy 
##                          11271.70                          14839.47 
##                           Jamaica                             Japan 
##                           1055.40                           9254.03 
##                            Jordan                        Kazakhstan 
##                           1709.77                          11887.95 
##                             Kenya                        Kyrgyzstan 
##                           -789.09                           -888.12 
##                            Latvia                           Lebanon 
##                          11134.51                           5969.64 
##                         Lithuania                        Madagascar 
##                          15086.29                          -2434.23 
##                            Malawi                          Malaysia 
##                          -2399.61                          12297.09 
##                              Mali                         Mauritius 
##                          -2092.34                           7779.15 
##                            Mexico                          Mongolia 
##                           6908.41                           3051.65 
##                           Morocco                           Namibia 
##                          -2019.72                           1177.81 
##                       Netherlands                       New Zealand 
##                          19131.27                          11953.38 
##                             Niger                           Nigeria 
##                          -3559.50                            451.06 
##                  North Macedonia*                            Norway 
##                           5673.76                           9748.64 
##                          Pakistan                            Panama 
##                            135.30                          13825.82 
##                          Paraguay                              Peru 
##                           3687.02                           2347.88 
##                       Philippines                            Poland 
##                           -445.59                          13610.61 
##                          Portugal                             Qatar 
##                          12035.27                          51803.34 
##           Republic of Korea (the)         Republic of Moldova (the) 
##                          14944.61                           3173.13 
##                           Romania                Russian Federation 
##                          11625.10                          13068.13 
##                            Rwanda                           Senegal 
##                          -3349.34                          -3225.32 
##                            Serbia                         Singapore 
##                           5041.12                          55264.25 
##                          Slovakia                          Slovenia 
##                          10986.98                          13998.47 
##                      South Africa                             Spain 
##                           4677.71                          13605.17 
##                         Sri Lanka                            Sweden 
##                           3520.65                          12389.19 
##                       Switzerland                        Tajikistan 
##                          18248.71                           -601.64 
##                          Thailand                           Tunisia 
##                           7274.06                           1262.54 
##                            Turkey                            Uganda 
##                          13918.04                          -3457.97 
##                           Ukraine                    United Kingdom 
##                           5456.15                          14376.84 
## United Republic of Tanzania (the)          United States of America 
##                          -3087.18                          22476.80 
##                           Uruguay                           Vietnam 
##                           5532.51                           1705.93 
##                            Zambia 
##                          -1373.18

Thus, we can omit the insignificant variables and obtain the following model

fixed2 <-plm(gdp1~institutions+infra+markets+gni, data=data, index=c("economy", "year"), model="within")
summary(fixed2)
## Oneway (individual) effect Within Model
## 
## Call:
## plm(formula = gdp1 ~ institutions + infra + markets + gni, data = data, 
##     model = "within", index = c("economy", "year"))
## 
## Balanced Panel: n = 105, T = 11, N = 1155
## 
## Residuals:
##        Min.     1st Qu.      Median     3rd Qu.        Max. 
## -11937.8250   -682.6737     -8.5379    725.5187  17926.6170 
## 
## Coefficients:
##                Estimate Std. Error t-value              Pr(>|t|)    
## institutions  50.759980  15.652419  3.2429               0.00122 ** 
## infra        175.291700   9.550920 18.3534 < 0.00000000000000022 ***
## markets      -66.600812  12.097855 -5.5052         0.00000004639 ***
## gni            0.457488   0.019909 22.9785 < 0.00000000000000022 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Total Sum of Squares:    6389800000
## Residual Sum of Squares: 3322100000
## R-Squared:      0.48009
## Adj. R-Squared: 0.42641
## F-statistic: 241.473 on 4 and 1046 DF, p-value: < 0.000000000000000222

Pooled OLS estimator

ols<-lm(gdp1~institutions+infra+markets+gni, data=data)

#test for poolability
pFtest(fixed2, ols)
## 
##  F test for individual effects
## 
## data:  gdp1 ~ institutions + infra + markets + gni
## F = 145.74, df1 = 104, df2 = 1046, p-value < 0.00000000000000022
## alternative hypothesis: significant effects
# Testing for serial correlation
pbgtest(fixed2)
## 
##  Breusch-Godfrey/Wooldridge test for serial correlation in panel models
## 
## data:  gdp1 ~ institutions + infra + markets + gni
## chisq = 558.1, df = 11, p-value < 0.00000000000000022
## alternative hypothesis: serial correlation in idiosyncratic errors
# Testing for heteroskedasticity
bptest(gdp1~institutions+infra+markets+gni, data=data, studentize=T)
## 
##  studentized Breusch-Pagan test
## 
## data:  gdp1 ~ institutions + infra + markets + gni
## BP = 274.64, df = 4, p-value < 0.00000000000000022
#controlling heteroskedascity
coeftest(fixed2, vcov.=vcovHC(fixed, method="white1", type="HC0", cluster="group"))
## 
## t test of coefficients:
## 
##                Estimate Std. Error t value              Pr(>|t|)    
## institutions  50.759980  13.817538  3.6736             0.0002513 ***
## infra        175.291700  11.802054 14.8526 < 0.00000000000000022 ***
## markets      -66.600812  18.742000 -3.5536             0.0003970 ***
## gni            0.457488   0.069292  6.6023      0.00000000006425 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1