Setting up environment

# List of packages
packages <- c("tidyverse", "infer", "fst", "modelsummary", "effects", "survey", "interactions") # 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)
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Task 1

Graph the histogram distribution using the populist scale (as we did in the tutorial) for the country of Sweden. What do you note?

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

sweden_data$trust <- scales::rescale(sweden_data$trstplt + sweden_data$trstprl + sweden_data$trstprt, na.rm = TRUE, to = c(0, 100))

sweden_data$populist <- scales::rescale(sweden_data$trust, na.rm = TRUE, to=c(100,0))
ggplot(sweden_data, aes(x = populist)) +
  geom_histogram(bins = 30, fill = "blue", color = "black") +
  theme_minimal() +
  labs(title = "Distribution of Populist Scale for Sweden",
       x = "Populist Scale",
       y = "Count")
## Warning: Removed 2503 rows containing non-finite values (`stat_bin()`).

#the data of the graph is skewed to the left side although the majority of the data sits in the middle. there is also a peak at 50 which shows the average level of populism in sweden.

Task 2

Run a linear regression with populist attitudes as the outcome, educational attainment (recoded as a binary “BA or more” and “No BA”), and using the Swedish data. Print the intercept and coefficients only and interpret. Then do a tidy model table displaying the p-value (with digits = 3) and interpret.

model.sweden_data <- sweden_data %>%
  mutate(
    
 # Recoding education
    educ.ba = case_when(
      essround < 5 & edulvla == 5 ~ "BA or more",
      essround >= 5 & edulvlb > 600 ~ "BA or more",
      TRUE ~ "No BA"
    ),
    
    # Handling NAs for education levels
    edulvla = ifelse(edulvla %in% c(77, 88, 99), NA_integer_, edulvla),
    edulvlb = ifelse(edulvlb %in% c(5555, 7777, 8888), NA_integer_, edulvlb),
    
    # Explicitly making 'No BA' the reference category
    educ.ba = factor(educ.ba, levels = c("No BA", "BA or more")),
)
sweden_model <- lm(populist ~ educ.ba, data = model.sweden_data)
coefficients_sweden <- coef(sweden_model)
print(coefficients_sweden)
##       (Intercept) educ.baBA or more 
##         51.358680         -7.868121

#the interceptions of 51.35 represents the average score on the populist scale when you do not have a BA degree. Whereas the -7.86 represents the difference of average score on the populist scale for individuals that have a BA degree which show that individuals with a BA have -7.86 points compared to the individual without a BA.

Task 3

Now using the Italian dataset and the authoritarian values scale (as we did in the tutorial), graph the average by survey year. Interpret.

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

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))
table(df$secure)
## 
##    1    2    3    4    5    6 
##   54  139  626 1856 2876 2881
df$year <- NA
replacements <- c(2002, 2004, 2006, 2008, 2010, 2012, 2014, 2016, 2018, 2020)
for(i in 1:10){
  df$year[df$essround == i] <- replacements[i]
}
auth_avg <- df %>%
  group_by(year) %>%
  summarize(auth_avg = mean(auth, na.rm = TRUE))

plot_auth <- ggplot(auth_avg, aes(x = year, y = auth_avg)) +
  geom_point(aes(color = auth_avg), alpha = 1.0) + 
  geom_line(aes(group = 1), color = "blue", linetype = "dashed") +  
  labs(title = "Authoritarian Scale Average by Year (Italy)",
       x = "Survey Year",
       y = "Authoritarian Scale Average") +
  theme_minimal() +
  theme(legend.position = "none") +
  scale_y_continuous(limits = c(0, 100))

print(plot_auth)

#the authoritarian scale for italy sits around and remains constant around 75 which proves there has not been any significant changes in authoritarian beliefs.

Task 4

Now run a linear regression model, using the modelsummary package, with authoritarian values as the outcome, and generations as the predictor/potential explanatory variable, and using the Italian data again. Rename the coefficients using the coef_rename function. Interpret the coefficients, whether they are statistically significant, and the adjusted R-squared.

model_data <- df %>%
  mutate(
    age = ifelse(agea == 999, NA, agea),

    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, 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(cohort)  
    ),

    gen = factor(gen,
                 levels = c("1", "2", "3", "4"),
                 labels = c("Interwar", "Baby Boomers", "Gen X", "Millennials"))
  )
table(model_data$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         1026         2580         2214         1811
model1 <- lm(auth ~ gen, data = model_data)
modelsummary(model1, fmt = 1,
  estimate  = c("{estimate} ({std.error}){stars}"),
  statistic = NULL,
  coef_rename = c("genBaby Boomers" = "Baby Boomers", "genGen X" = "Gen X", "genMillennials" = "Millennials"),
  title = 'Table 1. Regression models for authoritarian attitudes')
Table 1. Regression models for authoritarian attitudes
 (1)
(Intercept) 75.3 (0.5)***
Baby Boomers −1.1 (0.6)*
Gen X −2.1 (0.6)***
Millennials −3.6 (0.6)***
Num.Obs. 7631
R2 0.006
R2 Adj. 0.006
AIC 62934.0
BIC 62968.7
Log.Lik. −31462.009
RMSE 14.94

GenBaby Boomers (-1.1)- this represents that gen baby boomers on average have a 1.1 score lower than the interwar generation on the authoritarian scale

#GenX (-2.1)- this represents that Genx on averages has 2.1 score lower than the interwar generation on the authoritarian scale

#GenMillennials (-3.6)- this represents that Gen Millennials on average have a 3.6 score lower than the interwar generation on the authoritarian scale making it the largest difference which indicates millennials have the strongest difference to the interwar generation on the authoritarian scale.

R squared value 0.6% represents the variance of italian authoritarian value scale

Task 5

Now visualize, using the modelplot() function from the modelsummary package, coefficient estimates and 95% confidence intervals for the following three models:

Model 1 = populist attitudes scale as the outcome; left/right as the single predictor (omitting moderates as we did in the tutorial), and using data for Greece.

Model 2 = populist attitudes scale as the outcome; gender as the single predictor, and using data for Greece.

Model 3 = populist attitudes scale as the outcome; generations as the single predictor (using the four generational category recode we did in the tutorial), and using data for Greece. Interpret.

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

greece_data$trust <- scales::rescale(greece_data$trstplt + greece_data$trstprl + greece_data$trstprt, na.rm = TRUE, to = c(0, 100))

greece_data$populist <- scales::rescale(greece_data$trust, na.rm = TRUE, to=c(100,0))
model.greece_data <- greece_data %>%
  mutate(
    gndr = case_when(
      gndr == 1 ~ "Male",
      gndr == 2 ~ "Female",
      gndr == 9 ~ NA_character_,
      TRUE ~ as.character(gndr)
    ),

  ID = case_when(
      lrscale %in% 0:4 ~ "Left",                    
      lrscale %in% 6:10 ~ "Right",                   
      lrscale %in% c(77, 88, 99) ~ NA_character_,    
      TRUE ~ NA_character_                          
    ),

    age = ifelse(agea == 999, NA, agea),

    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, 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(cohort)  
    ),

    gen = factor(gen,
                 levels = c("1", "2", "3", "4"),
                 labels = c("Interwar", "Baby Boomers", "Gen X", "Millennials"))
  )
table(model.greece_data$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         2978         3484         3498         2330
model1 <- lm(populist ~ ID, data = model.greece_data)
model2 <- lm(populist ~ gndr, data = model.greece_data)
model3 <- lm(populist ~ gen, data = model.greece_data)
modelsummary(
  list(model1),
  fmt = 1,
  estimate  = c( "{estimate} ({std.error}){stars}"),
  statistic = NULL,
  coef_omit = "Intercept")
 (1)
IDRight −8.8 (0.6)***
Num.Obs. 4936
R2 0.037
R2 Adj. 0.036
AIC 44723.8
BIC 44743.3
Log.Lik. −22358.894
RMSE 22.44
models <- list(
   "Model 1" = lm(populist ~ lrscale, data = model.greece_data),
   "Model 2" = lm(populist ~ gndr, data = model.greece_data),
   "Model 3" = lm(populist ~ gen, data = model.greece_data))
modelsummary(models, fmt = 1,
  estimate  = c("{estimate} ({std.error}){stars}",
                "{estimate} ({std.error}){stars}",
                "{estimate} ({std.error}){stars}"),
  statistic = NULL)
Model 1  Model 2  Model 3
(Intercept) 67.5 (0.3)*** 70.0 (0.3)*** 65.8 (0.5)***
lrscale 0.1 (0.0)***
gndrMale −1.0 (0.5)*
genBaby Boomers 3.5 (0.7)***
genGen X 5.6 (0.7)***
genMillennials 5.8 (0.7)***
Num.Obs. 9823 9823 9562
R2 0.021 0.000 0.009
R2 Adj. 0.021 0.000 0.009
AIC 88667.6 88873.2 86473.9
BIC 88689.2 88894.8 86509.7
Log.Lik. −44330.802 −44433.590 −43231.944
RMSE 22.07 22.30 22.25
models <- list(
   "Model 1" <- lm(populist ~ ID, data = model.greece_data),
   "Model 2" <- lm(populist ~ gndr, data = model.greece_data),
   "Model 3" <- lm(populist ~ gen, data = model.greece_data))
modelplot(models, coef_omit = 'Interc')

#Considering gender, on average men in Greece score 1 point less compared to women on the populist scale which show women show stronger populist opinions than men. When we consider generational differences, gen x, millenials and baby boomers all have higher populist scores compared to the interwar generation. Millenials have 5.8 points more than the interwar generation which show how millenials have stronger populist opions compared to other generations in Greece. Baby boomers have 3.5 points higher than the interwar generation and Gen x with 5.6 points higher.

#THE END