R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see http://rmarkdown.rstudio.com.

When you click the Knit button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

summary(cars)
##      speed           dist       
##  Min.   : 4.0   Min.   :  2.00  
##  1st Qu.:12.0   1st Qu.: 26.00  
##  Median :15.0   Median : 36.00  
##  Mean   :15.4   Mean   : 42.98  
##  3rd Qu.:19.0   3rd Qu.: 56.00  
##  Max.   :25.0   Max.   :120.00

Including Plots

You can also embed plots, for example:

Note that the echo = FALSE parameter was added to the code chunk to prevent printing of the R code that generated the plot.

packages <- c("tidyverse", "infer", "fst", "modelsummary", "effects", "survey", "MASS", "aod", "interactions", "kableExtra", "flextable", "scales") # add any you need here

# Install packages if they aren't installed already
new_packages <- packages[!(packages %in% installed.packages()[,"Package"])]
if(length(new_packages)) install.packages(new_packages)

# Load the packages
lapply(packages, library, character.only = TRUE)
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.4     ✔ readr     2.1.4
## ✔ forcats   1.0.0     ✔ stringr   1.5.1
## ✔ ggplot2   3.4.4     ✔ tibble    3.2.1
## ✔ lubridate 1.9.3     ✔ tidyr     1.3.0
## ✔ purrr     1.0.2     
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
## Warning: package 'infer' was built under R version 4.3.3
## Warning: package 'effects' was built under R version 4.3.3
## Loading required package: carData
## Warning: package 'carData' was built under R version 4.3.3
## lattice theme set by effectsTheme()
## See ?effectsTheme for details.
## Warning: package 'survey' was built under R version 4.3.3
## Loading required package: grid
## Loading required package: Matrix
## 
## Attaching package: 'Matrix'
## 
## The following objects are masked from 'package:tidyr':
## 
##     expand, pack, unpack
## 
## Loading required package: survival
## 
## Attaching package: 'survey'
## 
## The following object is masked from 'package:graphics':
## 
##     dotchart
## 
## 
## Attaching package: 'MASS'
## 
## The following object is masked from 'package:dplyr':
## 
##     select
## Warning: package 'aod' was built under R version 4.3.3
## 
## Attaching package: 'aod'
## 
## The following object is masked from 'package:survival':
## 
##     rats
## Warning: package 'interactions' was built under R version 4.3.3
## 
## Attaching package: 'kableExtra'
## 
## The following object is masked from 'package:dplyr':
## 
##     group_rows
## Warning: package 'flextable' was built under R version 4.3.3
## 
## Attaching package: 'flextable'
## 
## The following objects are masked from 'package:kableExtra':
## 
##     as_image, footnote
## 
## The following object is masked from 'package:purrr':
## 
##     compose
## 
## 
## Attaching package: 'scales'
## 
## The following object is masked from 'package:purrr':
## 
##     discard
## 
## The following object is masked from 'package:readr':
## 
##     col_factor
## [[1]]
##  [1] "lubridate" "forcats"   "stringr"   "dplyr"     "purrr"     "readr"    
##  [7] "tidyr"     "tibble"    "ggplot2"   "tidyverse" "stats"     "graphics" 
## [13] "grDevices" "utils"     "datasets"  "methods"   "base"     
## 
## [[2]]
##  [1] "infer"     "lubridate" "forcats"   "stringr"   "dplyr"     "purrr"    
##  [7] "readr"     "tidyr"     "tibble"    "ggplot2"   "tidyverse" "stats"    
## [13] "graphics"  "grDevices" "utils"     "datasets"  "methods"   "base"     
## 
## [[3]]
##  [1] "fst"       "infer"     "lubridate" "forcats"   "stringr"   "dplyr"    
##  [7] "purrr"     "readr"     "tidyr"     "tibble"    "ggplot2"   "tidyverse"
## [13] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "methods"  
## [19] "base"     
## 
## [[4]]
##  [1] "modelsummary" "fst"          "infer"        "lubridate"    "forcats"     
##  [6] "stringr"      "dplyr"        "purrr"        "readr"        "tidyr"       
## [11] "tibble"       "ggplot2"      "tidyverse"    "stats"        "graphics"    
## [16] "grDevices"    "utils"        "datasets"     "methods"      "base"        
## 
## [[5]]
##  [1] "effects"      "carData"      "modelsummary" "fst"          "infer"       
##  [6] "lubridate"    "forcats"      "stringr"      "dplyr"        "purrr"       
## [11] "readr"        "tidyr"        "tibble"       "ggplot2"      "tidyverse"   
## [16] "stats"        "graphics"     "grDevices"    "utils"        "datasets"    
## [21] "methods"      "base"        
## 
## [[6]]
##  [1] "survey"       "survival"     "Matrix"       "grid"         "effects"     
##  [6] "carData"      "modelsummary" "fst"          "infer"        "lubridate"   
## [11] "forcats"      "stringr"      "dplyr"        "purrr"        "readr"       
## [16] "tidyr"        "tibble"       "ggplot2"      "tidyverse"    "stats"       
## [21] "graphics"     "grDevices"    "utils"        "datasets"     "methods"     
## [26] "base"        
## 
## [[7]]
##  [1] "MASS"         "survey"       "survival"     "Matrix"       "grid"        
##  [6] "effects"      "carData"      "modelsummary" "fst"          "infer"       
## [11] "lubridate"    "forcats"      "stringr"      "dplyr"        "purrr"       
## [16] "readr"        "tidyr"        "tibble"       "ggplot2"      "tidyverse"   
## [21] "stats"        "graphics"     "grDevices"    "utils"        "datasets"    
## [26] "methods"      "base"        
## 
## [[8]]
##  [1] "aod"          "MASS"         "survey"       "survival"     "Matrix"      
##  [6] "grid"         "effects"      "carData"      "modelsummary" "fst"         
## [11] "infer"        "lubridate"    "forcats"      "stringr"      "dplyr"       
## [16] "purrr"        "readr"        "tidyr"        "tibble"       "ggplot2"     
## [21] "tidyverse"    "stats"        "graphics"     "grDevices"    "utils"       
## [26] "datasets"     "methods"      "base"        
## 
## [[9]]
##  [1] "interactions" "aod"          "MASS"         "survey"       "survival"    
##  [6] "Matrix"       "grid"         "effects"      "carData"      "modelsummary"
## [11] "fst"          "infer"        "lubridate"    "forcats"      "stringr"     
## [16] "dplyr"        "purrr"        "readr"        "tidyr"        "tibble"      
## [21] "ggplot2"      "tidyverse"    "stats"        "graphics"     "grDevices"   
## [26] "utils"        "datasets"     "methods"      "base"        
## 
## [[10]]
##  [1] "kableExtra"   "interactions" "aod"          "MASS"         "survey"      
##  [6] "survival"     "Matrix"       "grid"         "effects"      "carData"     
## [11] "modelsummary" "fst"          "infer"        "lubridate"    "forcats"     
## [16] "stringr"      "dplyr"        "purrr"        "readr"        "tidyr"       
## [21] "tibble"       "ggplot2"      "tidyverse"    "stats"        "graphics"    
## [26] "grDevices"    "utils"        "datasets"     "methods"      "base"        
## 
## [[11]]
##  [1] "flextable"    "kableExtra"   "interactions" "aod"          "MASS"        
##  [6] "survey"       "survival"     "Matrix"       "grid"         "effects"     
## [11] "carData"      "modelsummary" "fst"          "infer"        "lubridate"   
## [16] "forcats"      "stringr"      "dplyr"        "purrr"        "readr"       
## [21] "tidyr"        "tibble"       "ggplot2"      "tidyverse"    "stats"       
## [26] "graphics"     "grDevices"    "utils"        "datasets"     "methods"     
## [31] "base"        
## 
## [[12]]
##  [1] "scales"       "flextable"    "kableExtra"   "interactions" "aod"         
##  [6] "MASS"         "survey"       "survival"     "Matrix"       "grid"        
## [11] "effects"      "carData"      "modelsummary" "fst"          "infer"       
## [16] "lubridate"    "forcats"      "stringr"      "dplyr"        "purrr"       
## [21] "readr"        "tidyr"        "tibble"       "ggplot2"      "tidyverse"   
## [26] "stats"        "graphics"     "grDevices"    "utils"        "datasets"    
## [31] "methods"      "base"

Task 1

Use data for Germany and the variable coding for model3 and model4 from the tutorial (i.e., both for the cleaning & recode, as well as the linear model formulas). Do a modelsummary table displaying both model outputs. Interpret the coefficients for the MLR without the interaction (i.e., the first displayed model), and interpret model fit metrics for both models.

Germany_data <- read.fst("Germany_data.fst")
Gf <- Germany_data
Gf$trstplt <- ifelse(Gf$trstplt > 10, NA, Gf$trstplt)
Gf$trstprl <- ifelse(Gf$trstprl > 10, NA, Gf$trstprl)
Gf$trstprt <- ifelse(Gf$trstprt > 10, NA, Gf$trstprt)

# Creating and rescaling the trust variable
Gf$trust <- scales::rescale(Gf$trstplt + Gf$trstprl + Gf$trstprt, na.rm = TRUE, to = c(0, 100))

# Here's how you would "flip it" because populist is conceived by N + I as 'anti-trust'
# As Schafer explains there are some issues with that conceptualization, but N + I is also widely applied
Gf$populist <- scales::rescale(Gf$trust, na.rm = TRUE, to=c(100,0))
Gf <- Gf %>%
  mutate(behave = ipbhprp,
         secure = impsafe,
         safety = ipstrgv,
         tradition = imptrad,
         rules = ipfrule) %>%
  mutate(across(c("behave", "secure", "safety", "tradition", "rules"),
                ~ na_if(.x, 7) %>% na_if(8) %>% na_if(9))) %>%
  # Apply the reverse coding
  mutate(across(c("behave", "secure", "safety", "tradition", "rules"), ~ 7 - .x ))

# Now you can calculate 'schwartzauth' after the NA recoding
Gf$auth <- scales::rescale(Gf$behave + 
                      Gf$secure + 
                      Gf$safety + 
                      Gf$tradition + 
                      Gf$rules, to=c(0,100), na.rm=TRUE)


Gf <- Gf %>% filter(!is.na(auth))
Gf <- Gf %>%
  mutate(
    polID = case_when(
      lrscale %in% 0:3 ~ "Left",                    
      lrscale %in% 7:10 ~ "Right",                     
      lrscale %in% 4:6 ~ "Moderate",                  
      lrscale %in% c(77, 88, 99) ~ NA_character_      
    ),
   religious = case_when(
      rlgdgr %in% c(77, 88, 99) ~ NA_real_,
      TRUE ~ rlgdgr
    )
  )
model3 <- lm(auth ~ polID + religious, data = Gf, weights = weight)
model4 <- lm(auth ~ polID + religious + polID*religious, data = Gf, weights = weight)
modelsummary(
  list(model3, model4),
  fmt = 1,
  estimate  = c( "{estimate} ({std.error}){stars}",
                "{estimate} ({std.error}){stars}"),
  statistic = NULL)
 (1)   (2)
(Intercept) 57.5 (0.7)*** 59.6 (0.9)***
polIDModerate 5.3 (0.7)*** 2.6 (1.1)*
polIDRight 9.3 (1.1)*** 3.4 (1.9)+
religious 0.3 (0.1)** −0.3 (0.2)+
polIDModerate × religious 0.8 (0.2)**
polIDRight × religious 1.5 (0.4)***
Num.Obs. 2855 2855
R2 0.035 0.041
R2 Adj. 0.034 0.039
AIC 24680.0 24665.5
BIC 24709.7 24707.2
Log.Lik. −12334.978 −12325.764
RMSE 17.13 17.13

#the intercept for the first group is 57.5 with a standard error of 0.7, and for the second group, it’s 59.6 with a standard error of 0.9. The asterisks denote the level of statistical significance, with three asterisks indicating a highly significant result. the polIDModerate variable represents the effect of being identified as “Moderate” on the dependent variable. In the first group, being identified as “Moderate” increases the dependent variable by 5.3 units, with a standard error of 0.7. In the second group, the effect is 2.6 units with a standard error of 1.1. Both effects are statistically significant (denoted by three asterisks for the first group and one asterisk for the second group). the polIDRight variable represents the effect of being identified as “Right” on the dependent variable. In the first group, being identified as “Right” increases the dependent variable by 9.3 units, with a standard error of 1.1. In the second group, the effect is 3.4 units with a standard error of 1.9. Both effects are statistically significant (three asterisks for the first group and a plus sign for the second group, indicating marginal significance). the religious variable represents the effect of religiosity on the dependent variable. In the first group, an increase in religiosity by one unit leads to a 0.3 unit increase in the dependent variable, with a standard error of 0.1. In the second group, the effect is a decrease of 0.3 units, with a standard error of 0.2. The first effect is statistically significant (two asterisks), while the second effect is not. polIDModerate × religious is the interaction term which represents the effect of the interaction between being identified as “Moderate” and religiosity on the dependent variable. The coefficient is 0.8 with a standard error of 0.2, indicating that the effect of being identified as “Moderate” varies depending on religiosity. The effect is statistically significant (two asterisks).

Task 2

Now generate the model4 interaction plot that we did in the tutorial, but again using the German data instead of the French. Interpret.

interaction_plot <- effect("polID*religious", model4, na.rm=TRUE)

plot(interaction_plot,
     main="Interaction effect",
     xlab="Religiousness",
     ylab="Authoritarian attitudes scale")

interaction_plot
## 
##  polID*religious effect
##           religious
## polID             0        2        5        8       10
##   Left     59.61010 58.93398 57.91980 56.90562 56.22950
##   Moderate 62.21299 63.14317 64.53843 65.93370 66.86388
##   Right    63.00456 65.26702 68.66072 72.05442 74.31689

Task 3

Use data for the Netherlands and the variable coding for model5 and model6 from the tutorial (i.e., both for the cleaning & recode, as well as the linear model formulas). Do a modelsummary table displaying both model outputs. Interpret the coefficients for the MLR without the interaction (i.e., the first displayed model), and interpret model fit metrics for both models.

Netherlands_data <- read.fst("Netherlands_data.fst")
Nf <- Netherlands_data
Nf$trstplt <- ifelse(Nf$trstplt > 10, NA, Nf$trstplt)
Nf$trstprl <- ifelse(Nf$trstprl > 10, NA, Nf$trstprl)
Nf$trstprt <- ifelse(Nf$trstprt > 10, NA, Nf$trstprt)

# Creating and rescaling the trust variable
Nf$trust <- scales::rescale(Nf$trstplt + Nf$trstprl + Nf$trstprt, na.rm = TRUE, to = c(0, 100))

# Here's how you would "flip it" because populist is conceived by N + I as 'anti-trust'
# As Schafer explains there are some issues with that conceptualization, but N + I is also widely applied
Nf$populist <- scales::rescale(Nf$trust, na.rm = TRUE, to=c(100,0))
Nf <- Nf %>%
  mutate(behave = ipbhprp,
         secure = impsafe,
         safety = ipstrgv,
         tradition = imptrad,
         rules = ipfrule) %>%
  mutate(across(c("behave", "secure", "safety", "tradition", "rules"),
                ~ na_if(.x, 7) %>% na_if(8) %>% na_if(9))) %>%
  # Apply the reverse coding
  mutate(across(c("behave", "secure", "safety", "tradition", "rules"), ~ 7 - .x ))

# Now you can calculate 'schwartzauth' after the NA recoding
Nf$auth <- scales::rescale(Nf$behave + 
                      Nf$secure + 
                      Nf$safety + 
                      Nf$tradition + 
                      Nf$rules, to=c(0,100), na.rm=TRUE)


Nf <- Nf %>% filter(!is.na(auth))
Nf <- Nf %>%
  mutate(religion = case_when(
    rlgblg == 2 ~ "No",
    rlgblg == 1 ~ "Yes",
    rlgblg %in% c(7, 8, 9) ~ NA_character_,
    TRUE ~ as.character(rlgblg)
  ))

# check
table(Nf$religion)
## 
##    No   Yes 
## 10913  6750
Nf <- Nf %>%
  mutate(ID = case_when(
    lrscale >= 0 & lrscale <= 4 ~ "Left",
    lrscale >= 6 & lrscale <= 10 ~ "Right",
    lrscale > 10 ~ NA_character_,  # Set values above 10 as NA
    TRUE ~ NA_character_  # Ensure value 5 and any other unexpected values are set as NA
  ))
table(Nf$ID)
## 
##  Left Right 
##  5449  7010
Nf <- Nf %>%
  mutate(
    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, yrbrn),
    # Recoding generational cohorts based on the year of birth (yrbrn).
    # The year of birth is categorized into different generational cohorts.
    # Interwar (1900-1945), Baby Boomers (1946-1964), Gen X (1965-1979), Millennials (1980-1996).
    # The 'TRUE' line is a catch-all that keeps the original year of birth for those not in these ranges.
    gen = case_when(
      yrbrn %in% 1900:1945 ~ "1",
      yrbrn %in% 1946:1964 ~ "2",
      yrbrn %in% 1965:1979 ~ "3",
      yrbrn %in% 1980:1996 ~ "4",
      TRUE ~ as.character(yrbrn)  
    ),
    # After recoding, the gen variable is converted into a factor with labels for clearer interpretation.
    # Factors are used in R to handle categorical variables.
    gen = factor(gen,
                 levels = c("1", "2", "3", "4"),
                 labels = c("Interwar", "Baby Boomers", "Gen X", "Millennials"))
  )
table(Nf$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         3771         6147         4548         2730
model5 <- lm(auth ~ religion + ID + gen, data = Nf, weights = weight)
model6 <- lm(auth ~ religion + ID + gen + religion*gen, data = Nf, weights = weight)
modelsummary(
  list(model5, model6),
  fmt = 1,
  estimate  = c( "{estimate} ({std.error}){stars}",
                "{estimate} ({std.error}){stars}"),
  statistic = NULL,
  coef_omit = "Intercept")
 (1)   (2)
religionYes 8.2 (0.9)*** 7.5 (2.1)***
IDRight 3.4 (0.9)*** 3.4 (0.9)***
genBaby Boomers −5.8 (1.3)*** −6.5 (1.7)***
genGen X −7.3 (1.4)*** −7.6 (1.8)***
genMillennials −8.6 (1.5)*** −8.6 (1.9)***
religionYes × genBaby Boomers 1.6 (2.6)
religionYes × genGen X 0.5 (2.8)
religionYes × genMillennials −0.6 (3.2)
Num.Obs. 1147 1147
R2 0.126 0.127
R2 Adj. 0.123 0.121
AIC 9479.3 9484.5
BIC 9514.7 9535.0
Log.Lik. −4732.669 −4732.251
RMSE 14.94 14.94

Task 4

Produce the model7 interaction plot from the tutorial, but again using the Netherlands data. Interpret.

Nf <- Nf %>%
  mutate(
    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, yrbrn),
    # Recoding generational cohorts based on the year of birth (yrbrn).
    # The year of birth is categorized into different generational cohorts.
    # Interwar (1900-1945), Baby Boomers (1946-1964), Gen X (1965-1979), Millennials (1980-1996).
    # The 'TRUE' line is a catch-all that keeps the original year of birth for those not in these ranges.
    gen = case_when(
      yrbrn %in% 1900:1945 ~ "1",
      yrbrn %in% 1946:1964 ~ "2",
      yrbrn %in% 1965:1979 ~ "3",
      yrbrn %in% 1980:1996 ~ "4",
      TRUE ~ as.character(yrbrn)  
    ), 
    gen = factor(gen,
                 levels = c("1", "2", "3", "4"),
                 labels = c("Interwar", "Baby Boomers", "Gen X", "Millennials"))
  )
table(Nf$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         3771         6147         4548         2730
Nf <- Nf %>%
  mutate(
    polID = case_when(
      lrscale %in% 0:3 ~ "Left",                    
      lrscale %in% 7:10 ~ "Right",                     
      lrscale %in% 4:6 ~ "Moderate",                  
      lrscale %in% c(77, 88, 99) ~ NA_character_      
    ),
   religious = case_when(
      rlgdgr %in% c(77, 88, 99) ~ NA_real_,
      TRUE ~ rlgdgr
    )
  )
model7 <- lm(auth ~ + cohort + polID + cohort*polID, data = Nf, weights = weight)
interact_plot(model7, pred = cohort, modx = polID, jnplot = TRUE)

Task 5

Produce the model8 interaction plot from the tutorial, but again using the Netherlands data. Interpret.

model8 <- lm(auth ~ religious + ID + religious*ID, data = Nf, weights = weight)
interact_plot(model8, pred = religious, modx = ID, jnplot = TRUE)

End