This paper derives, and then estimates, a model of employment where unions and firms bargain over wages and possibly employment, and efficiency wage considerations may be important. It illustrates the difficulties associated in interpreting many existing attempts to discriminate between alternative models. The results (based on over 200 U.K. firms) suggest that employment is negatively related to the firm's own wage and the change in the own wage relative to outside opportunities. The latter may be an efficiency wage effect. Various financial factors are also seen to have a significant effect on employment.

Are people right to think that competition improves corporate performance? My investigations indicate first that there are some theoretical reasons for believing this hypothesis to be correct, but they are not overwhelming. Furthermore, the existing empirical evidence on this question is weak. However, the results reported here, based on an analysis of around 670 U.K. companies, do provide some support for this view. Most important, I present evidence that competition, as measured by increased numbers of competitors or by lower levels of rents, is associated with a significantly higher rate of total factor productivity growth.

Are people right to think that competition improves corporate performance? The author's investigations indicate first that there are some theoretical reasons for believing this hypothesis to be correct but they are not overwhelming. Furthermore, the existing empirical evidence on this question is weak. However, the results reported here, based on the analysis of around 670 U.K. companies, provide some support for this view. Most important, the author presents evidence that competition, as measured by increased numbers of competitors or by lower levels of rents, is associated with a significantly higher rate of total factor productivity growth. Copyright 1996 by University of Chicago Press.

The authors consider an economy in which all firms are unionized and bargain with their own union. If unions bargain over employment as well as wages, employment will be the same as if they bargain over wages only, provided that the production function is Cobb-Douglas. (Employment will be higher if the elasticity of substitution between labor and capital is smaller than unity.) If the authors start from a fully competitive labor market and then move to one of efficient bargaining (over wages and employment), employment falls. This is so even if the marginal utility of income is constant, so that bargaining is "strongly efficient."

The paper develops a simple iterative procedure for deriving linear decision rules which provide the optimal control policy for a stochastic dynamic linear system. The procedure works for a quadratic objective function with any time horizon up to and including infinity, either with or without time discounting. The role of target variables is conisidered and there is a discussion of the results which ensue if these targets are incompatible, that is, if they do not satisfy the underlying structural model. The paper concludes with some consideration of the convergence and other properties of the controlled system. THIS PAPER DEVELOPS a simple iterative method for deriving linear decision rules which provide the control policy for a stochastic dynamic linear system which is optimal for a quadratic criterion. The basic theory in economics was developed by Holt, Simon, Theil, Phillips, and others2 in the fifties and has recently been extended by Aoki [1], Chow [2 and 3], and Turnovsky [10]. The method described here is similar to that used by Chow [3] where the dynamic structure of the model is used to develop a suitable iterative procedure. This procedure is computationally simple, of low dimensionality, and may be applied to a system with any number of lags, irrespective of whether it is stable or unstable. For economic applications, the underlying system would typically be an econometric model in reduced form which has either been specially estimated as a completely linear model or has been suitably linearized. In Section 2 of the paper we derive a general procedure for solving an infinite horizon quadratic programming problem, proving both its convergence and optimality properties. In Sections 3 and 4 we discuss how this procedure may be adapted to solve finite and infinite horizon stochastic control problems and demonstrate some properties of the optimal path. Since the method produces an analytically explicit solution we are enabled to develop some further convergence properties of the infinite horizon, optimal path in Section 5. The specific control problem to be discussed in this paper is one of the following

In this paper, we first present a competitive macroeconomic model of an open economy which is suitable for estimation and contrast this with a non-competitive model. We then derive unemployment equations from the various models and estimate them over annual data from 1948–1979. We draw the following conclusions. (i) The competitive model of the labour market does not fit the facts. (ii) The non-competitive model generates an equation for the constant inflation rate of unemployment which reveals how, at certain times such as the mid 1970s, a combination of factors conspired to raise this level forcing the government into a deflationary stance to prevent inflation rising drastically. (iii) A number of factors have raised the level of unemployment in a secular fashion since the war, in particular the increase in the variation of relative prices, the increase in the benefit to income ratio, the introduction of employment protection legislation and the rise in the intersectoral shifts of the labour force.