The literature on R&D contests implicitly assumes that contestants submit their innovation regardless of its value. This ignores a potential adverse selection problem. The present paper analyzes the procurement of innovations when the procurer cannot commit to never bargain with innovators who bypass the contest. We compare fixed-prize tournaments with and without entry fees, and optimal scorin...

This paper studies the core of combined games, obtained by summing two coalitional games. It is shown that the set of balanced transferable utility games can be partitioned into equivalence classes of component games whose core is equal to the core of the combined game. On the other hand, for non balanced games, the binary relation associating two component games whose combination has an empty ...

This paper extends the formulation of complementarity in Milgrom and Shannon (1994) to the case of incomplete but acyclic preferences. It is shown that the problem can be reformulated as one with complete but intransitive preferences. In this case, quasi-supermodularity and single-crossing on their own do not guarantee either monotone comparative statics or equilibrium existence in pure strateg...

We consider a multimarket framework where a set of firms compete on two interrelated oligopolistic markets. Prior to competing in these markets, firms can spy on others in order to increase the quality of their product. We characterize the equilibrium espionage networks and networks that maximize social welfare under the most interesting scenario of diseconomies of scope. We find that in some s...

This paper studies games in which the players are not locked into their relationship for a fixed number of periods. We consider two-player games where player 1 can decide to let the opponent continue in the game or replace it with a new player. We also allow the possibility of player 2 quitting the game. When only layoffs can occur, cooperation takes place in finite horizons due to the threat t...

A discrete public good is provided when total contributions exceed the contribution threshold, yet the threshold is often not known with certainty. I show that the relationship between the degree of threshold uncertainty and equilibrium contributions and welfare is not monotonic. For a large class of threshold probability distributions, equilibrium contributions will be higher under increased u...

In the canonical network model, the connections model, only three specific network structures are generically efficient: complete, empty, and star networks. This renders many plausible network structures inefficient. We show that requiring robustness with respect to stochastic transmission failures rehabilitates incomplete, circular network structures. Specifically, we show that near the “bifur...

In an environment with dynamic arrivals of players who wish to purchase only one of multiple identical objects for which they have a private value, we analyze a sequential auction mechanism with an activity rule. If the players play undominated strategies then we are able to bound the efficiency loss compared to an optimal mechanism that maximizes the total welfare. We have no assumptions on th...

Owing amongst other to its high electron mobility, fullerene C70, has been widely used as an electron transporting layer in organic solar cells. In this research, we report the use of C70 thin films as electron transport layers of planar perovskite solar cells (PSCs) using a conventional device structure. The thickness of the C70 layer has been optimized to achieve the best efficiency of 12%. I...

The frictional behaviors of fullerenes C60 and C70 were studied because they were speculated to be solid lubricants. For the sublimated pure C60 films on Si(001), a high friction coefficient (0.55–0.8) was observed under different loads and pin materials. For the C70 film, the friction coefficient showed a pin dependence, which changed from 0.5 with an Al2O3 pin to about 0.9 with a 440 stainles...