# Introducing the Democratic Electoral Systems data, 1919-1945

## TL;DR

This paper introduces updated data on electoral systems in 34 democracies from 1919 to 1945, including election rules and outcomes.

## Contribution

The paper provides a new dataset covering interwar electoral systems with compatibility to prior data and multiple democracy classifications.

## Key findings

- The dataset includes 243 elections with variables on electoral rules and outcomes.
- Four democracy classifications are included for user flexibility.
- Identification variables allow linking to other datasets.

## Abstract

This data note introduces an update to the widely-used Democratic Electoral Systems (DES) data that encompasses the period from 1919 to 1945. The data include 243 legislative lower house and presidential elections in 34 interwar democracies. Information on these elections falls into four categories: first and foremost, DES contains variables that capture the institutional rules that define how elections are organized. Second, the data captures the consequences of electoral rules in the form of summary statistics of electoral outcomes. Third, we include democracy classifications for four major democracy datasets so that users can choose their preferred democracy definition when working with the data. Finally, the DES dataset contains multiple identification variables that allow linking the DES data to a wide variety of other datasets. This update to the DES data is fully compatible with prior releases for the post-war period

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We provide information on electoral rules between 1919 and 1945. We focus on parliamentary and presidential elections in democracies. We collect information on these rules in a dataset of 243 elections. Many rules exist. Some describe how many members a parliament has. Others determine where politicians are elected. Again others decide how individual votes a party needs to get a seat. We also describe the consequences of elections, for example, how many parties make it into parliament. There are different ways to think about what democracy is. Our dataset uses four different approaches to determine whether or not a country is a democracy so users can decide which elections to consider democratic. Our data can also be linked to many other data sources.