Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty.

This study explores how researchers' analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers' expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team's workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers' results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings.

How and why party position estimates from manifestos, expert, and party elite surveys diverge: A comparative analysis of the 'left-right' and the 'European integration' dimensions.

This paper examines the validity of three approaches to estimate party positions on the general left-right and EU dimensions. We newly introduce party elite data from the comprehensive IntUne survey and cross-validate it with existing expert survey and manifesto data. The general left-right estimates generated by elites and experts show a higher congruence than those derived from party manifestos; neither measure clearly materializes as more valid regarding EU positions. We identify which factors explain diverging estimates. For instance, disagreement among experts has greater impact than their mere number. The substantial centrist bias of the manifesto estimates persists even when alternative documents are used to substitute manifestos. Low response rates among elites have no systematic detrimental effect on the validity of party position estimates.

The distribution of individual cabinet positions in coalition governments: A sequential approach.

Multiparty government in parliamentary democracies entails bargaining over the payoffs of government participation, in particular the allocation of cabinet positions. While most of the literature deals with the numerical distribution of cabinet seats among government parties, this article explores the distribution of individual portfolios. It argues that coalition negotiations are sequential choice processes that begin with the allocation of those portfolios most important to the bargaining parties. This induces conditionality in the bargaining process as choices of individual cabinet positions are not independent of each other. Linking this sequential logic with party preferences for individual cabinet positions, the authors of the article study the allocation of individual portfolios for 146 coalition governments in Western and Central Eastern Europe. The results suggest that a sequential logic in the bargaining process results in better predictions than assuming mutual independence in the distribution of individual portfolios.