Overview

The package offers functions that calculate coalition probabilities in multi-party elections, based on a survey results:

Installation

Install from GitHub using:

devtools::install_github("adibender/coalitions", build_vignettes=TRUE)

Usage

Detailed workflow is outlined in the vignettes enclosed in the package (see browseVignettes(package="coalitions")).

A short overview is presented below.

Scrape surveys

The wrapper get_surveys() which takes no arguments, downloads all surveys currently available at wahlrecht.de and stores them in a nested tibble:

library(coalitions)
library(dplyr)
library(tidyr)
surveys <- get_surveys()
surveys
## # A tibble: 7 x 2
##   pollster   surveys           
##   <chr>      <list>            
## 1 allensbach <tibble [41 × 5]> 
## 2 emnid      <tibble [222 × 5]>
## 3 forsa      <tibble [231 × 5]>
## 4 fgw        <tibble [82 × 5]> 
## 5 gms        <tibble [96 × 5]> 
## 6 infratest  <tibble [107 × 5]>
## 7 insa       <tibble [301 × 5]>

Each row represents a survey insitute and each row in the surveys column again contains a nested tibble with survey results from different time-points:

surveys %>%
    filter(pollster == "allensbach") %>%
    unnest()
## # A tibble: 41 x 6
##    pollster   date       start      end        respondents survey         
##    <chr>      <date>     <date>     <date>           <dbl> <list>         
##  1 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 <tibble [7 × 3…
##  2 allensbach 2017-12-21 2017-12-01 2017-12-14        1443 <tibble [7 × 3…
##  3 allensbach 2017-11-30 2017-11-22 2017-11-27        1299 <tibble [7 × 3…
##  4 allensbach 2017-10-25 2017-10-07 2017-10-19        1454 <tibble [7 × 3…
##  5 allensbach 2017-09-22 2017-09-13 2017-09-20        1074 <tibble [7 × 3…
##  6 allensbach 2017-09-19 2017-09-06 2017-09-14        1083 <tibble [7 × 3…
##  7 allensbach 2017-09-06 2017-08-22 2017-08-31        1043 <tibble [7 × 3…
##  8 allensbach 2017-08-22 2017-08-04 2017-08-17        1421 <tibble [7 × 3…
##  9 allensbach 2017-07-18 2017-07-01 2017-07-12        1403 <tibble [7 × 3…
## 10 allensbach 2017-06-20 2017-06-01 2017-06-15        1437 <tibble [7 × 3…
## # ... with 31 more rows
survey <- surveys %>% unnest() %>% slice(1)
survey %>% unnest()
## # A tibble: 7 x 8
##   pollster   date       start      end        respondents party  percent
##   <chr>      <date>     <date>     <date>           <dbl> <chr>    <dbl>
## 1 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 cdu      34.0 
## 2 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 spd      21.0 
## 3 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 greens   10.5 
## 4 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 fdp      10.0 
## 5 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 left      8.50
## 6 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 afd      12.0 
## 7 allensbach 2018-01-25 2018-01-05 2018-01-18        1221 others    4.00
## # ... with 1 more variable: votes <dbl>

Calculate coalition probabilities

For each survey (row) we can calculate the coalition probabilities

survey %>% get_probabilities(nsim=1e4) %>% unnest()
## # A tibble: 6 x 4
##   pollster   date       coalition       probability
##   <chr>      <date>     <chr>                 <dbl>
## 1 allensbach 2018-01-25 cdu                   0    
## 2 allensbach 2018-01-25 cdu_fdp               0.210
## 3 allensbach 2018-01-25 cdu_fdp_greens       99.8  
## 4 allensbach 2018-01-25 spd                   0    
## 5 allensbach 2018-01-25 left_spd              0    
## 6 allensbach 2018-01-25 greens_left_spd       0