The equilibrium set of two-player games with complementarities is a sublattice

Summary. I prove that the equilibrium set in a two-player game with complementarities, and totally ordered strategy spaces, is a sublattice of the joint strategy space. Received: May 31, 2001; revised version: October 4, 2002     

Extensive-form games and strategic complementarities

I prove the subgame-perfect equivalent of the basic result for Nash equilibria in normal-form games of strategic complements: the set of subgame-perfect equilibria is a nonempty, complete lattice—in particular, subgame-perfect Nash equilibria exist. For this purpose I introduce a device that allows the study of the set of subgame-perfect equilibria as the set of fixed points of a correspondence. My results are limited because extensive-form games of strategic complementarities turn out—surprisingly—to be a very restrictive class of games.     

Complementarities between firm-sponsored training and information technology use

In this article, we investigate the presence of possible complementarities between investments in information technology (IT) and firm-sponsored training using economy-wide longitudinal representative workplace-level data. Since information on the firm’s capital stock is often missing in such representative data, we match our workplace records to tax data to construct measures of the firm’s capital stock. We find some evidence of positive complementarities between investments in human capital and IT, suggesting that on-the-job training can also have a positive impact on productivity when complemented with investments in CAD or other technologies.     

Network games with incomplete information

We consider a network game with strategic complementarities where the individual reward or the strength of interactions is only partially known by the agents. Players receive different correlated signals and they make inferences about other players’ information. We demonstrate that there exists a unique Bayesian-Nash equilibrium. We characterize the equilibrium by disentangling the information effects from the network effects and show that the equilibrium effort of each agent is a weighted combinations of different Katz–Bonacich centralities.     

The dark and the bright side of liquidity risks: Evidence from open-end real estate funds in Germany

During the 6-month period from December 2005 to June 2006, the German Real Estate mutual fund industry suffered an unprecedented liquidity crisis. We investigate to what extend competing theories of liquidity crises help explain this event. Our results show that fundamental factors not only mattered for the liquidity outflow in normal times but also during the crisis. However, strategic complementarities accelerated the withdrawals during the crisis suggesting that pure panic behavior contributed substantially to the massive outflows. Thus higher liquidity buffers might help mitigating these tail events. Furthermore, we find that funds with a lower fraction of shares held by institutional investors suffered from less significant outflows suggesting that a segmentation of funds for different investor groups might help mitigate panics.     

中英货物贸易的比较优势和贸易互补性的实证分析

中英两国经贸往来历史悠久,但两国双边贸易仅占两国对外贸易额的10%左右。笔者利用RCA指数、IIT指数以及TCI指数分析中英货物贸易的比较优势和贸易互补性,指出中英货物贸易今后的发展方向。     

Strategic complementarities and nested potential games

This paper reports that every finite game of strategic complementarities is a nested pseudo-potential game defined by Uno [Uno, H., 2007. Nested potential games. Economics Bulletin 3(17), 1–8] if the action set of each player is one-dimensional, except possibly for one player.     

Finite supermodular design with interdependent valuations

This paper studies supermodular mechanism design in environments with arbitrary (finite) type spaces and interdependent valuations. In these environments, the designer may have to use Bayesian equilibrium as a solution concept, because ex-post implementation may not be possible. We propose direct (Bayesian) mechanisms that are robust to certain forms of bounded rationality while controlling for equilibrium multiplicity. In quasi-linear environments with informational and allocative externalities, we show that any Bayesian mechanism that implements a social choice function can be converted into a supermodular mechanism that also implements the original decision rule. The proposed supermodular mechanism can be chosen in a way that minimizes the size of the equilibrium set, and we provide two sets of sufficient conditions to this effect. This is followed by conditions for supermodular implementation in unique equilibrium.     

When trade hurts: Consumption indivisibilities and labor market distortions

We present a simple model where complementarities between wages and demand due to factor market distortions can make a transition economy worse off from trade. Prior to trade, a virtuous circle prevails: high wages in industry support a high demand for indivisible industrial goods, which in turn supports high wages. However, factor market distortions in the transition economy create a comparative disadvantage in industry. Opening up to trade results in the import of indivisibles and a fall in manufacturing wages, breaking this virtuous circle. Consequently, trade liberalization without structural reform can have serious adverse effects in a transition economy.