Politics in the Courtroom: Political Ideology and Jury Decision Making

This paper uses data from the Gothenburg District Court in Sweden and a research design that exploits the random assignment of politically appointed jurors (termed nämndemän) to make three contributions to the literature on jury decision-making: (i) an assessment of whether systematic biases exist in the Swedish nämndemän system, (ii) causal evidence on the impact of juror political party on verdicts, and (iii) an empirical examination of the role of peer effects in jury decision-making. The results reveal a number of systematic biases: convictions for young defendants and those with distinctly Arabic names increase substantially when they are randomly assigned jurors from the far-right (nationalist) Swedish Democrat party, whereas convictions in cases with a female victim increase markedly when they are assigned jurors from the far-left (feminist) Vänster party. An analysis of peer effects implies that jurors from the far-left and far-right parties influence the votes of nämndemän from centrist parties in a way that is consistent with their respective party platforms. This analysis also suggests that at least some of these peer effects result in genuine changes of opinions (affecting trial outcomes), rather than vote changes motivated solely to reach unanimous decisions.