Heresthetics and choice from tournaments

Abstract

Moser et al. provide a formalization of heresthetics, the “art of political strategy”, in collective choice settings. In doing so they introduce the heresthetically stable set as the set of outcomes least susceptible to manipulation of issue dimension. In this note we correct a small error in the original paper, and close several open questions asked there in. We examine the heresthetically stable set as a tournament solution, establishing some basic properties it possesses, and many it does not posses. In addition, we relate the heresthetically stable set to other tournament solutions, notably the weak uncovered and refinements thereof. We find lack of vulnerability to heresthetic manipulation is contrary to many desirable properties of choice functions, notably majoritarian support.

Deciding on What to Decide

“…Our analysis also points at an additional form of manipulation that may be in the hands of a chair, as we already announced. Typically, chairs can manipulate sequential voting procedures by adding new alternatives to the list of possible ones (see Moser et al., 2009; and Moser, Fenn et al., 2016) and/or by changing the order of vote once the set of alternatives is given. What we find is that, in addition, the chair may induce agenda setters to change the set of issues (hence the characteristics of the set of available alternatives) under sequential voting procedures by simply announcing the order in which alternatives will be presented for a vote.…”