# 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)

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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")
# Setting values greater than 10 to NA
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)

# Creating and rescaling the trust variable
sweden_data$trust <- scales::rescale(sweden_data$trstplt + sweden_data$trstprl + sweden_data$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
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()`).

therefore, the produced histogram is right skewed meaning that populism occurs mostly at lower levels. therefore the approximate mode would be below 50.

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.

sweden_data <- sweden_data %>%
  mutate(
    educ.ba = case_when(
      essround < 5 & edulvla == 5 ~ "BA or more",
      essround >= 5 & edulvlb > 600 ~ "BA or more",
      TRUE ~ "No BA"
    ),
    
    edulvla = ifelse(edulvla %in% c(77, 88, 99), NA_integer_, edulvla),
    edulvlb = ifelse(edulvlb %in% c(5555, 7777, 8888), NA_integer_, edulvlb),
    
    educ.ba = factor(educ.ba, levels = c("No BA", "BA or more"))
  )
sweden_pop_model <- lm(populist ~ educ.ba, data = sweden_data)
coefficients_sweden <- coef(sweden_pop_model)
print(coefficients_sweden)
##       (Intercept) educ.baBA or more 
##         51.358680         -7.868121
broom::tidy
## Registered S3 methods overwritten by 'broom':
##   method            from  
##   tidy.glht         jtools
##   tidy.summary.glht jtools
## function (x, ...) 
## {
##     UseMethod("tidy")
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## <environment: namespace:generics>
tidy(sweden_pop_model)
## # A tibble: 2 × 5
##   term              estimate std.error statistic   p.value
##   <chr>                <dbl>     <dbl>     <dbl>     <dbl>
## 1 (Intercept)          51.4      0.181     283.  0        
## 2 educ.baBA or more    -7.87     0.350     -22.5 2.58e-110
tidy(sweden_pop_model) |>
knitr::kable(digits = 3)
term estimate std.error statistic p.value
(Intercept) 51.359 0.181 283.363 0
educ.baBA or more -7.868 0.350 -22.494 0
summary(sweden_pop_model)
## 
## Call:
## lm(formula = populist ~ educ.ba, data = sweden_data)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -51.359 -14.692  -1.359  11.975  56.509 
## 
## Coefficients:
##                   Estimate Std. Error t value Pr(>|t|)    
## (Intercept)        51.3587     0.1812  283.36   <2e-16 ***
## educ.baBA or more  -7.8681     0.3498  -22.49   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 19.43 on 15711 degrees of freedom
##   (2503 observations deleted due to missingness)
## Multiple R-squared:  0.0312, Adjusted R-squared:  0.03114 
## F-statistic:   506 on 1 and 15711 DF,  p-value: < 2.2e-16

therefore, the intercept is 51.35 which represents the average level of populist attitudes among people who do not have bachelors degree whereas the coefficient is -7.86 meaning that people with bachelors degrees have populist attitudes that are lower by -7.86 in comparison to people who don’t have their bachelors. we can conclude that having higher education levels is connected to lower levels of populist attitudes.

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.

italy_data <- read.fst("italy_data.fst")
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))) %>%
  # 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))
table(df$secure)
## 
##    1    2    3    4    5    6 
##   54  139  626 1856 2876 2881
table(df$auth)
## 
##   0  12  16  20  24  28  32  36  40  44  48  52  56  60  64  68  72  76  80  84 
##   7   4   4   9  13  20  27  57 113 155 163 323 367 596 647 789 823 897 992 733 
##  88  92  96 100 
## 632 465 299 297
ggplot(df, aes(x = auth)) +
  geom_histogram(bins = 30, fill = "blue", color = "black") +
  theme_minimal() +
  labs(title = "Distribution of Authoritarian Scale for italy",
       x = "Authoritarian Scale",
       y = "Count")

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)

therefore, the visualization shows a stable lien through 2012-2016, from 2016 to 2020 there is a very slight decrease which is from 75 to approximately 74.

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)
models <- list(
   "model 1" = lm(auth ~ gen, data = model_data))
modelsummary(models, 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 2. Regression models for authoritarian attitudes')
Table 2. Regression models for authoritarian attitudes
model 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

Therefore, we can see that the coefficient is negative which means that baby boomers have lower levels of authoritarianism which is by 1.1, as well there is not a trippel asterisk meaning that the value si not much lower that 0.5. As for gen x this means that it has a low authoritarianism by 2.1 than the groups. Moving on, millennials have a low authoritarianism by 3.6 compared to the groups, the three asterisks displayed indicates that coefficient is significant at the 0.001 level instead of 0.05 (*).as well the R2 value is at 0.006 which represents the proportion of vairnance in authoritarianism by generational cohorts. We can conclude that there are many factors influencing authoritarianism.

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")

model 1

# Read in the Sweden dataset:
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))

# Recode lrscale variable
greece_data <- greece_data %>%
  mutate(
    ID = case_when(
      lrscale %in% 0:4 ~ "Left",                     # This time: Values 0 to 3 in 'lrscale' are categorized as "Left"
      lrscale %in% 6:10 ~ "Right",                   # This time: Values 6 to 10 in 'lrscale' are categorized as "Right"
      lrscale %in% c(77, 88, 99) ~ NA_character_,    # Values 77, 88, 99 in 'lrscale' are set as NA
      TRUE ~ NA_character_                           # Any other values not explicitly matched above
    )
  )

greece_lr_model <- lm(populist ~ ID, data = greece_data)

model 2

# Recode gender
greece_data <- greece_data %>%
  mutate(
    # Recoding gender
    gndr = case_when(
      gndr == 1 ~ "Male",
      gndr == 2 ~ "Female",
      gndr == 9 ~ NA_character_,
      TRUE ~ as.character(gndr)
    ))

greece_gndr_model <- lm(populist ~ gndr, data = greece_data)

model 3

greece_data <- greece_data %>%
  mutate(
    # Recoding cohort variable, setting years before 1930 and after 2000 to NA
    cohort = ifelse(yrbrn < 1930 | yrbrn > 2000, NA, yrbrn),

    # Recoding generational cohorts based on year of birth
    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)  # Keeping other values as character if they do not fit the ranges
    ),

    # Converting cohort to a factor with labels
    gen = factor(gen,
                 levels = c("1", "2", "3", "4"),
                 labels = c("Interwar", "Baby Boomers", "Gen X", "Millennials"))
  )
table(greece_data$gen)
## 
##     Interwar Baby Boomers        Gen X  Millennials 
##         2978         3484         3498         2330
models <- list(
   "Model 1" = lm(populist ~ ID, data = greece_data),
   "Model 2" = lm(populist ~ gndr, data = greece_data),
   "Model 3" = lm(populist ~ gen, data = 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) 72.0 (0.5)*** 70.0 (0.3)*** 65.8 (0.5)***
IDRight −8.8 (0.6)***
gndrMale −1.0 (0.5)*
genBaby Boomers 3.5 (0.7)***
genGen X 5.6 (0.7)***
genMillennials 5.8 (0.7)***
Num.Obs. 4936 9823 9562
R2 0.037 0.000 0.009
R2 Adj. 0.036 0.000 0.009
AIC 44723.8 88873.2 86473.9
BIC 44743.3 88894.8 86509.7
Log.Lik. −22358.894 −44433.590 −43231.944
RMSE 22.44 22.30 22.25
modelplot(models, coef_omit = 'Interc')

For model 1, it is a left to right predictor, the intercept coefficient of 72,0 states the expected value of populist attitudes when the left/right score is zero. The coefficient for the ID right is -8.8(p<0,001) meaning that for every increase in the left/right score, there is a decrease of 8.8 nits in populist attitudes. The r2 means that 3.7% of the variance in populist attitudes is a result of the left/right score

For model 2, it is a genders predictor, the intercept coefficient of 70.0 is the expected value of populist attitudes for females. For gndrMale, the coefficient of -1.0 means that males have 1.0 unit lower populist attitudes compared to females. The r2 is 0 meaning that the gender variable doesnt impact varaince in populist attitudes.

For model 3, it is a generation predictor, the intercept coefficient of 65.8 stands for the value of populist attitudes for the reference generation (Interwar). The coefficients under genBaby Boomers, genGen X, millennial represent the difference compared to generation as baby boomers have 3.5 units higher in populist attitudes, gen x has 5.6 units higher and millennials have 5.8 units higher. The r2 is 0.9% representing the variance in populist attitudes by the generational categories.

End