# List of packages
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     2.1.5
## ✔ 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
## Loading required package: carData
## 
## lattice theme set by effectsTheme()
## See ?effectsTheme for details.
## 
## 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
## 
## 
## 
## Attaching package: 'aod'
## 
## 
## The following object is masked from 'package:survival':
## 
##     rats
## 
## 
## 
## Attaching package: 'kableExtra'
## 
## 
## The following object is masked from 'package:dplyr':
## 
##     group_rows
## 
## 
## 
## 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")
df <- germany_data
df$weight <- df$dweight * df$pweight
survey_design <- svydesign(ids = ~1, data = df, weights = ~weight)

##authoritarian scale

df <- df %>%
  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
df$auth <- scales::rescale(df$behave + 
                      df$secure + 
                      df$safety + 
                      df$tradition + 
                      df$rules, to=c(0,100), na.rm=TRUE)


df <- df %>% filter(!is.na(auth))

#add some covariates of interest

df <- df %>%
  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 = df, weights = weight)
model4 <- lm(auth ~ polID + religious + polID*religious, data = df, weights = weight)
modelsummary(
  list(model3, model4),
  fmt = 1,
  estimate  = c( "{estimate} ({std.error}){stars}",
                "{estimate} ({std.error}){stars}"),
  statistic = NULL)
 (1)   (2)
(Intercept) 55.3 (0.3)*** 56.4 (0.3)***
polIDModerate 4.6 (0.3)*** 3.4 (0.4)***
polIDRight 7.7 (0.4)*** 4.2 (0.7)***
religious 0.9 (0.0)*** 0.6 (0.1)***
polIDModerate × religious 0.3 (0.1)***
polIDRight × religious 0.8 (0.1)***
Num.Obs. 23373 23373
R2 0.048 0.050
R2 Adj. 0.048 0.050
AIC 200594.1 200558.6
BIC 200634.4 200615.0
Log.Lik. −100292.049 −100272.298
RMSE 17.27 17.24

Task1 answer: - polIDModerate (4.6): This coefficient suggests that, comparing individuals with the same religiousness , the average outcome for individuals identifying as politically moderate are 4.6 units higher compared to the reference group which :identifying ideologically as on the ‘left’). The “baseline group” refers to the category that is omitted, and is thus interpreted as part of our intercept.

All three coefficients have ***, indicating a p < 0.001. Meaning: There is less than a 0.1% probability that the observed result is due to chance and we incorrectly reject the null, under frequentist assumptions.

When interpreting the intercept (55.3 in the MLR), it represents the expected value of the authoritarian score in German when the polID are set to ‘left’, and religiousness is set to zero.

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     56.40706 57.56775 59.30879 61.04983 62.21053
##   Moderate 59.85063 61.66176 64.37844 67.09513 68.90626
##   Right    60.60237 63.35032 67.47224 71.59416 74.34211

Task2 answer: According to the plots, the slope of these three lines are different, therefore the interaction effect exists. Also, the slopes of all three line are positive, religiousness and authoritarian score are postively related.

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.

##load data

netherlands_data <- read_fst("netherlands_data.fst")
df1 <- netherlands_data
df1$weight <- df1$dweight * df1$pweight
survey_design <- svydesign(ids = ~1, data = df, weights = ~weight)
df1 <- df1 %>%
  mutate(
    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, yrbrn),
    # Recoding generational cohorts based on the year of birth (yrbrn).
   
    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(df1$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         3967         6359         4684         2803

#set up authoritarian scale

df1 <- df1 %>%
  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))) %>%
  
  mutate(across(c("behave", "secure", "safety", "tradition", "rules"), ~ 7 - .x ))


df1$auth <- scales::rescale(df1$behave + 
                      df1$secure + 
                      df1$safety + 
                      df1$tradition + 
                      df1$rules, to=c(0,100), na.rm=TRUE)


df1 <- df1 %>% filter(!is.na(auth))
df1 <- df1 %>%
  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
    )
  )
df1 <- df1 %>%
  mutate(religion = case_when(
    rlgblg == 2 ~ "No",
    rlgblg == 1 ~ "Yes",
    rlgblg %in% c(7, 8, 9) ~ NA_character_,
    TRUE ~ as.character(rlgblg)
  ))


table(df1$religion)
## 
##    No   Yes 
## 10913  6750
df1 <- df1 %>%
  mutate(ID = case_when(
    lrscale >= 0 & lrscale <= 4 ~ "Left",
    lrscale >= 6 & lrscale <= 10 ~ "Right",
    lrscale > 10 ~ NA_character_,  
    TRUE ~ NA_character_  
  ))
table(df1$ID)
## 
##  Left Right 
##  5449  7010
df1 <- df1 %>%
  mutate(
    # Recoding the 'ppltrst' variable, which seems to measure trust on a scale from 0 to 10.
    # Special codes like 77, 88, 99 are probably used for missing data and are set to NA.
    # Trust levels are categorized as 'Low', 'Mid', and 'High'.
    Capital = case_when(
      ppltrst %in% c(77, 88, 99) ~ NA_character_,
      ppltrst >= 0 & ppltrst <= 3 ~ "Low",
      ppltrst >= 4 & ppltrst <= 6 ~ "Mid",
      ppltrst >= 7 & ppltrst <= 10 ~ "High",
      TRUE ~ as.character(ppltrst)
    ),
    # Recoding 'polintr' variable, which seems to measure political interest.
    # Values of 1 and 2 indicate 'Interested', 3 and 4 'Not Interested'.
    # Special codes like 7, 8, 9 (likely missing data) are set to NA.
    Politically = case_when(
      polintr %in% c(1, 2) ~ "Interested",
      polintr %in% c(3, 4) ~ "Not Interested",
      polintr %in% c(7, 8, 9) ~ NA_character_
    )
  )
model5 <- lm(auth ~ religion + ID + gen, data = df1, weights = weight)
model6 <- lm(auth ~ religion + ID + gen + religion*gen, data = df1, 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 7.2 (0.3)*** 5.7 (0.7)***
IDRight 4.2 (0.3)*** 4.3 (0.3)***
genBaby Boomers −5.2 (0.4)*** −5.9 (0.6)***
genGen X −7.7 (0.4)*** −8.8 (0.6)***
genMillennials −8.4 (0.5)*** −9.7 (0.6)***
religionYes × genBaby Boomers 1.1 (0.8)
religionYes × genGen X 2.3 (0.9)**
religionYes × genMillennials 2.9 (1.0)**
Num.Obs. 12116 12116
R2 0.124 0.125
R2 Adj. 0.124 0.125
AIC 101219.3 101213.5
BIC 101271.2 101287.5
Log.Lik. −50602.672 −50596.757
RMSE 15.27 15.26

task3 answer: religionYes (7.2): This coefficient suggests that, people from the group ‘religionYes’, on average, have74.2 higher auth score than who are politically left

IDRight (4.2): This coefficient suggests that, people who are politically right are expected, on average, have 4.2 higher auth score than who are politically left

genBaby Boomers (-5.2): This coefficient suggests that, Baby Boomers are expected, on average, have 5.2 lower auth score than the reference generational cohort.

genGen X (-7.7): This coefficient suggests that, people from group Gen X are expected, on average, have 7.7 lower auth score than the reference category.

genMillennials (-8.4): This coefficient suggests that, people from group millennials are expected, on average, have 8.4 lower auth score than the reference category.

All five coefficients have ***, indicating a p < 0.001. This means there is less than a 0.1% probability that the observed result is due to chance and we incorrectly reject the null, under frequentist assumptions.

Task 4

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

model7 <- lm(auth ~ + cohort + polID + cohort*polID, data = df1, weights = weight)
interact_plot(model7, pred = cohort, modx = polID, jnplot = TRUE)

Task4 answer: According to the plot, as the cohort, the auth score decreases. Also, the slopes of three lines are different, it suggests that there an interaction effect between them.

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 = df1, weights = weight)
interact_plot(model8, pred = religious, modx = ID, jnplot = TRUE)

Task5 answer: According to the plot, as the religious increases, the auth score increases as well. Also, the slope of two lines(politically left and politically right) are pretty close, it suggests that there is no interaction effect between them.