Knowledge that Transforms

[It is well known that in the Sidrauski monetary intertemporal optimizing model the steady state capital stock is invariant to the rate of inflation. This paper shows that the rate of accumulation of capital is not invariant to the rate of inflation and that, for the constant relative risk aversion family of utility functions (except logarithmic), the rate of capital accumulation is faster the higher the growth rate of money. Money is thus not neutral on transition paths.]

Sample selection bias as a specification error This paper discusses the bias that results from using non-randomly selected samples to estimate behavioral relationships as an ordinary specification error or «omitted variables» bias. A simple consistent two stage estimator is considered that enables analysts to utilize simple regression methods to estimate behavioral functions by least squares methods. The asymptotic distribution of the estimator is derived.

Collective choice problems are studied from the Bayesian viewpoint. It is shown that the set of expected utility allocations which are feasible with incentive-compatible mechanisms is compact and convex, and includes the equilibrium allocations for all other mechanisms. The generalized Nash solution proposed by Harsanyi and Selten is then applied to this set to define a bargaining solution for Bayesian collective choice problems.

[The purpose of this paper is to amend some of Hannan's [6] identification results for ARMAX models and to discuss identification in ARMAX models when identities are present. In addition, we briefly discuss how the ARMAX results can be adapted to obtain identification conditions for dynamic simultaneous equations models with autoregressive disturbances.]

[This paper describes a simple, operational procedure that, under reasonable economic assumptions, always generates Pareto-efficient egalitarian-equivalent allocations (PEEEA) when agents know each other's preferences. The procedure constitutes a new, constructive proof of Pazner and Schmeidler's theorems on the existence of PEEEA, and shows that PEEEA, like fair and Pareto-efficient allocations, can be decentralized using less information than is required by the standard market procedure for decentralizing allocations that maximize a neoclassical, individualistic social welfare function.]

[If buyers are less well-informed about product quality than sellers, market prices will reflect average quality. Sellers of high quality products therefore have an incentive to engage in some distinguishing activity which operates as a signal to potential buyers. This paper explores the viability of such signalling or "informational equilibria." It is established that with a continuum of quality levels there is no Nash equilibrium. An alternative non-cooperative equilibrium concept is then developed in which potential price searching agents take account of possible reactions by other agents. It is shown that there is a unique "reactive" informational equilibrium.]

HANS KEIDING of the University of Copenhagen has pointed out that Theorem (3.1) of our recent paper [1] is false as stated. In particular he has illustrated that when n = 2, using the notation of [1], one can construct a proper (1) correspondence Z: S2 -> P(R2) satisfying Definition (3.3) and such that Z(p) c 4th quadrant, for each p E S2. By Walras' Law this means Z'(p) 0 only when p = (1, 0). Thus, if S c Sn satisfies Z(p) s 0 for all p E S, then S = {(0, 1)}, which is not a subset of full dimensionality in Sn. We remedy this by adding to Definition (3.3) the economically innocuous assumption that if a good's price be zero the excess demand for it will be positive: