Antipartisanship - an explanation for extremism?

I adapt the Hotelling-Downs (Anthony Downs, 1957) framework for political decision-making and add an ''antipartisan''-component. Antipartisans (or negative voters) vote for the party located furthest away from the party they dislike most on the political spectrum. Besides the commonly-known edge-case (no Nash equilibrium in pure strategies), the introduction of antipartisanship gives rise to other empirically-speaking, familiar pure strategy equilibria not captured by standard models. I determine all stable outcomes: in equilibrium, parties might spread over the spectrum (distinct positions), locate on extreme positions, or no equilibrium exists.

The model provides a theoretical explanation for phenomena such as those observed in Brazil in 2018 and Germany in 2014: an increase in the share of anitpartisans, triggered by some exogenous event (like a scandal or the refugee crisis in Europe), followed by relocation on the political spectrum and a transition to a new equilibrium. I characterise the conditions under which such relocations can be explained solely by a change in the share of antipartisans.

Code for Theorem 2': part 1 and part 2

Age-weighted voting.

In times of ageing populations, intergenerational conflicts of interest have become increasingly prominent in public discussions. Votes on pension schemes or the ”Brexit”-vote are just two examples putting emphasis on the importance of such conflicts in collective choice. An apparent solution would be the weighting of votes according to voters’ ages. While such weighting scheme is undoubtedly very unlikely to ever be implemented, this analysis could serve as a benchmark to answer the question ”What if we were to weight agents’ votes by the extend to which they will be exposed to the election’s outcome? How would a fair society decide taking into account voters being affected to differing degrees?”.
Besides the general election framework, one could think of any other setting in which weights are correlated
with interests: Think of a committee deciding over a potential raise in wages for an airline’s employees. The
committee consists of the CEO, a major shareholder, a representative of the workers’ council and a chairman of the trade-union. While the CEO and the shareholder are in favour of the status quo, the other members would prefer a raise in wages. Power comes with liability/responsibility and so it could well be that the CEO’s and the shareholder’s vote matter more. Thereby, interest is correlated with weight in this setting as well.

This project sketches a way to evaluate such weighted voting mechanisms with respect to welfare considerations, information aggregation, strategic voting and the like. While the intuitive answer to these questions would be that voters with higher weights profit from such weighting schemes and welfare increases if we integrate voters’ utility over future years, it is not clear ex-ante whether this is also the correct one. Due to strategic voting, adverse effects might arise: Feddersen and Pesendorfer (1998) for instance find that, while unanimity voting is supposed to reduce the probability of implementing an inefficient policy, compared to majority voting, it might lead do the exact opposite.

Collective Choice lecture

(script only, lecture held by Stephan Lauermann)

  •  Pivotal or ethical voting - a comparison of two heuristics.

  •  Condorcet Jury and costly voting - experimental evidence.