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.,...

We prove a general possibility result for collective decision problems where individual allocations are one-dimensional, preferences are single-peaked (strictly convex), and feasible allocation profiles cover a closed convex set. Special cases include the celebrated median voter theorem (Black...

Median voter theorem has been used in many economic environments including law enforcement. Assumptions of the median voter theorem, however, are generally violated in lawenforcement models. Moreover, it is impossible to have agents with "opposite equilibrium preferences" over enforcement levels...

A small committee has to approve/reject a project with uncertain return. Members have different preferences: some are value-maximizers, others are biased towards approval. We focus on the efficient use of scarce information when communication is not guaranteed, and we provide insights on the...

The burgeoning literature on the use of sanctions to support public goods provision has largely neglected the use of formal or centralized sanctions. We let subjects playing a linear public goods game vote on the parameters of a formal sanction scheme capable both of resolving and of...

We study the interdependence of optimal tax and expenditure policies. An optimal policy requires that information on preferences is made available. We first study this problem from a general mechanism design perspective and show that efficiency is possible only if the individuals who decide on...

When making collektive desicions, principals (voters or districts) typically benefit by strategically delegating their bargaining and voting power to representatives different from themselves. There are conflicting views in the literature, however, of whether such a delegate should be...

A collective decision problem is described by a set of agents, a profile of single-peaked preferences over the real line and a number k of public facilities to be located. We consider public facilities that do not suffer from congestion and are non-excludable. We provide a characterization of...

We set up a model of elections or referendums with two alternatives to study how voter turnout and election outcomes are affected by the publication of exit polls on election day. We find that the introduction of an exit poll influences the incentive to vote both before and after the poll is...