A hierarchical agency model of deposit insurance

This paper develops a hierarchical agency model of deposit insurance. The main purpose of the analysis is to propose a micro-founded model of deposit insurance schemes and study their effects on the behavior of depositors and the monitoring problem for a bank. This paper also characterizes a risk-based premium in equilibrium, and conducts a comparative statics analysis of depositors’ optimal actions. The results supply the basic theoretical foundation for designing deposit insurance schemes. Our findings are consistent with the empirical research on depositor behavior.     

A unifying impossibility theorem

This paper identifies and illuminates a common impossibility principle underlying a number of impossibility theorems in social choice. We consider social choice correspondences assigning a choice set to each non-empty subset of social alternatives. Three simple axioms are imposed as follows: unanimity, independence of preferences over infeasible alternatives, and choice consistency with respect to choices out of all possible alternatives. With more than three social alternatives and the universal preference domain, any social choice correspondence that satisfies our axioms is serially dictatorial. A number of known impossibility theorems—including Arrow’s Impossibility Theorem, the Muller–Satterthwaite Theorem, and the impossibility theorem under strategic candidacy—follow as corollaries.     

A dynamic strategy of the informed trader with market manipulation

This paper considers stock price manipulation by a dynamic informed trader. We provide a simple proof of the existence of manipulation in a market in a standard sequential trade model. We also give the lower bound of the number of trading periods for the existence of manipulation in equilibrium and show that if the number of trading periods is larger than that lower bound, every equilibrium involves stock price manipulation. Irrespective of the prior of the market maker, if the informed trading probability is high enough, every equilibrium involves manipulation.     

Office-seeking politicians, interest groups and split contributions in a campaign finance model

The present paper investigates an extended version of Prat's campaign finance models. In this model, interest groups make contributions to politicians to influence policy decisions. Voters are assumed to judge candidates on two aspects: policy promises and nonpolicy personal qualities referred to as valence. There are two types of voters. Among these, uninformed voters only observe campaign contributions that take the role of a signaling medium. We solve the equilibrium of the game between politicians and interest groups. We then specify conditions under which a separating equilibrium exists and study the effect of split contributions on the welfare of the median voter.     

Nash equilibrium and party polarization in an electoral model with mixed motivations

We study the existence problem of Nash equilibrium as well as the patterns of equilibrium policy outcomes in an electoral competition model with mixed motivations. Each party maximizes a sum of party members’ expected utility and office rent. The inclusion of office rent renders the payoff of each party discontinuous. This makes it difficult to apply usually fixed point arguments to prove the existence of Nash equilibria. By using a recently developed concept, multiple restrictional security (MR‐security) we provide conditions under which a pure‐strategy Nash equilibrium exists within fairly general settings, and further the analysis by presenting conditions under which various patterns of policy choices, including polarization, arise in equilibrium.     

Retailer Market Concentration,Buyer‐Size Discounts and Inflation Dynamics

This study considers the macroeconomic effects of retailer market concentration and buyer‐size discounts on inflation dynamics. During Japan's “lost decades”, large retailers enhanced their market power, thus increasing the exploitation of buyer‐size discounts in the procurement of goods. We incorporate this effect into an otherwise standard New Keynesian model. Calibrating to the Japanese economy during the lost decades, we find that these developments led to a deflation of approximately 0.1% annually.