R Package

The gerda R package provides tools to download and work with GERDA datasets directly in R. Current version: 0.4.0 (CRAN).

Installation

# Install from CRAN
install.packages("gerda")

# Or install development version from GitHub
devtools::install_github("hhilbig/gerda")

Main Functions

Data Loading

• gerda_data_list(print_table = TRUE): Lists all available GERDA datasets with descriptions.
  • print_table: If TRUE (default), prints a formatted table and invisibly returns a tibble. If FALSE, returns the tibble directly.
• load_gerda_web(file_name, verbose = FALSE, file_format = "rds"): Loads a GERDA dataset from the web.
  • file_name: Dataset name (see gerda_data_list() for options).
  • verbose: Print loading messages (default FALSE).
  • file_format: File format to download, "rds" or "csv" (default "rds").
  • Includes fuzzy matching for file names and suggests close matches if exact match isn’t found.

Covariates

• add_gerda_covariates(): Appends socioeconomic indicators (population, unemployment, etc.) to election datasets. Use with piped data.

• gerda_covariates(): Returns raw covariate data as a standalone dataset for manual merging.

• gerda_covariates_codebook(): Returns the codebook with variable descriptions and metadata for all covariates.

Party Mapping

• party_crosswalk(party_gerda, destination): Maps GERDA party names to corresponding values from the ParlGov database.
  • party_gerda: Character vector of party names.
  • destination: Target column name from ParlGov crosswalk.

Usage Examples

library(gerda)

# List available datasets
gerda_data_list()

# Load harmonized municipal election data
municipal <- load_gerda_web("municipal_harm", verbose = TRUE)

# Load federal county data with socioeconomic covariates
federal_county <- load_gerda_web("federal_cty_harm") %>%
  add_gerda_covariates()

# View covariate definitions
gerda_covariates_codebook()

# Map party names to ParlGov
party_crosswalk(c("cdu_csu", "spd", "gruene"), "party_name_english")

Documentation

• Vignette: Introduction to gerda
• Reference Manual (PDF)
• GitHub Repository

Feedback

Feedback is welcome. Please email hhilbig@ucdavis.edu or open an issue on GitHub.