This paper examines the impact of payment choice on charitablegiving with a door-to-door fund-raising field experiment. Respondentscan donate cash only, use debit only, or have both options. Cash donations have lower visibility vis-a-vis solicitors than debit card donations. When debit replaces...

This paper extends Hotelling's model of price competition with quadratic transportation costs from a line to graphs. I propose an algorithm to calculate firm-level demand for anygiven graph, conditional on prices and firm locations. These graph models of price competitionmay lead to spatial...

Empirical studies of labor markets show that social contacts are an important source of job-related information [Ioannides and Loury (2004)]. At the same time, wage differences among workers may be explained only in part by differences in individual background characteristics. Such findings...