Though not conceived as a constant, the natural unemployment rate was taken to be invariant to supply shocks until the late seventies and to real demand shocks until now. The largely micro-theoretic model here is one in a series deriving the natural rate path from general equilibrium. In this model the labor market exhibits generalized real-wage rigidity, resulting from the use of "incentive wages" to combat shirking, and the asset backing shares is the firms' customers, arising from customer-market friction. One finding is that increased consumer demand drives up the natural rate by driving real interest rates up.

Laboratory data from bargaining experiments have started a debate about the prospects for various parts of game theory as descriptive theories of observable behavior, and about whether, to what extent, and how a successful descriptive theory must take into account peoples' perceptions of “fairness.” Plausible explanations of the observed bargaining phenomena advanced by different investigators lead to markedly different predictions about what should be observed in three different games. A sharp experimental test is thus possible on this class of games, and the present paper reports the results of such a test.