We consider the problem of covering the complete r-uniform hypergraphs on n vertices using complete r-partite graphs. We obtain lower bounds on the size of such a covering. For small values of r our result implies a lower bound of Ω( e r r √ r n log n) on the size of any such covering. This improves the previous bound of Ω(rn log n) due to Snir [5]. We also obtain good lower bounds on the size ...

This paper analyzes the role of yardstick competition for improving political decisions. We examine how performance comparisons across jurisdictions affect the agency problem resulting from uncertainty about politicians (adverse selection) and their policies (moral hazard). We study two forms of inefficiency: the provision of wasteful project and the failure to provide useful project .We find a...

In this paper I study the link between innovation efforts, competition, and aggregate uncertainty. A productive sector consists in a continuum of duopolies that face a stochastic aggregate demand. In each industry the two firms choose their level of innovation through intertemporal optimization given their respective market power in the business. Since competition in the model lessens ex ante p...

This paper studies how the real exchange rate changes with economic growth. Although Devereux (1999) proves that endogenous growth in the distribution sector can cause exchange rate depreciation, MacDonald and Rucci (2005) empirically find that growth in the distribution sector significantly causes the exchange rate to appreciate. To resolve the discrepancy, we replace perfect competition with ...

This paper studies a one-shot inventory replenishment problem with dynamic pricing. The customer arrival rate is assumed to follow a geometric Brownian motion. Homogeneous customers have an isoelastic demand function and do not behave strategically. We find a closed-form optimal pricing policy, which utilizes current demand information. Under this pricing policy the inventory trajectory is dete...

Heritable symbioses can have important ecological effects and have triggered important evolutionary innovations. Current predictions for long-term symbiont prevalence are based on their fitness benefits and vertical transmission rates but ignore nonlinear competitive feedbacks among symbiotic and symbiont-free hosts. We hypothesized that such feedbacks function as stabilizing mechanisms, promot...

Relational governance works well in relatively small communities, which may be too small to allow perfect competition. This paper explores this idea using two models. In a spatial model with monopolistic competition, relational governance constrains the size of firms and can lead to inefficiently excessive entry. In a model where high quality is self-enforcing because its providers get a suffic...

A linear (qd, q, t)-perfect hash family of size s in a vector space V of order qd over a field F of order q consists of a set φ1, . . . , φs of linear functionals from V to F with the following property: for all t subsets X ⊆ V there exists i ∈ {1, . . . , s} such that φi is injective when restricted to F . A linear (qd, q, t)-perfect hash family of minimal size d(t− 1) is said to be optimal. I...