Firms selling multiple quality-differentiated products frequently alter their product lines when a competitor enters the market. We present a model of multiproduct monopoly and duopoly using a general `upgrades` approach that yields a powerful analytical framework. We provide a simple...

We model the interplay between a government's performance, its expected lifetime, and the confidence it enjoys. Here, "confidence" can be broadly interpreted as the government's popularity, the size of its parliamentary majority, its reserve of talent, or other factors. Confidence evolves in...

We study a Cournot industry in which each firm sells multiple quality-differentiated products. We use an upgrades approach, working not with the actual products but instead with upgrades from one quality to the next. The properties of single-product models carry over to the supply of upgrades,...

This is an analysis of strategic voting under the qualified majority rule. Existing formal analyses of the plurality rule predict the complete coordination of strategic voting: A strict interpretation of Duvergers Law. This conclusion is rejected. Unlike previous models, the popular support for...

This is an analysis of strategic voting under the plurality rule. Existing theories predict strict bipartism, where rational voters support only two candidates: a strict interpretation of Duvergers Law. This conclusion is rejected. The new theory employs a simple model of a three-candidate...

This paper takes a new look at the classic concession game. It argues that exit from an asymmetric war of attrition is likely to be instant. Selecting a unique equilibrium using a craziness perturbation device, it finds a notion of stochastic strength determines the outcome, with a...

This is an analysis of strategic voting under qualified majority voting. Existing formal analyses of the plurality rule predict complete coordination of strategic voting: a strict interpretation of Duverger's Law. This conclusion is rejected. Unlike previous models, the popular support for each...