We introduce a binding unanimous voting rule to a public goods game with an uncertain threshold for the total group contribution. In a laboratory experiment we find that voting generates significantly higher total contributions than making individual voluntary contributions to the public good....

The outcomes of the 2013 German Bundestag (federal parliament) election are analyzed from the viewpoint of direct democracy. For this purpose, the party positions on 36 topical issues are compared with the results of public opinion polls, and the party and coalition indices of popularity (the...

We study a voting model with partial information in which the evaluation of social welfare must be based on information about agents' top choices plus qualitative background conditions on preferences. The former is elicited individually, while the latter is not. The social evaluator is modeled...

We critically discuss the Jefferson/D'Hondt and Webster/Sainte-Laguë methods, which are used to allocate parliament seats to parties in the mixed-member proportional representation systems in Germany, New Zealand, Bolivia, South Africa, South Korea, Scotland and Wales, as well as in the...

This is the third out four papers on the 2025 German Bundestag elections continuing our analysis of the 2009, 2013, 2017 and 2021 elections. In particular, this paper contributes to the discussion of the imperfection of the German 2023/24 Electoral reform in [Tangian 2025a]. We show that policy...

This is the last out of four papers on the 2025 German federal elections continuing our analysis of the 2009, 2013, 2017 and 2021 Bundestag elections. First, we apply the model from [Tangian 2022b] to construct the 2025 German political spectrum understood as a contiguous party ordering, i.e.,...

This is the first of four articles on the 2025 German federal elections, continuing our analysis of the 2009, 2013, 2017 and 2021 elections. We begin with the 2023/24 electoral reform, which aimed to curb the uncontrolled growth of the Bundestag caused by political developments not envisaged in...

This is the second out of four papers on the 2025 German federal elections continuing our analysis of the 2009, 2013, 2017 and 2021 Bundestag elections. We estimate the policy representation ability of the 29 parties that participated in the 2025 elections and of the 2025 Bundestag. For this...

We reappraise the Arrow problem by studying the aggregation of choice functions. We do so in the general framework of judgment aggregation, in which choice functions are naturally representable by specifying, for each menu A and each alternative x in A, whether x is choosable from A, or not. Our...

We study the aggregation of partial orders into a complete ordering, and prove both possibility and impossibility results in this context. First, we show that the standard independence of irrelevant alternatives condition is stronger here since even dictatorial aggregation rules may fail to...