Nested identification of subjective probabilities

The theory of games against nature relies on complete preferences among all conceivable acts, i.e. among all potential assignments of consequeces to states of nature (case 1). Yet most decision problems call for choosing an element from a limited set of acts. And in games of strategy, the set of strategies available to a player is givent and not amenable to artificial extensions. In “Assessing Strategic Risk”,(ECON DP 2005-20) R.J. Aumann and J.H. Drèze extend the basic result of decision theory (maximisation of subjectvely expected utility) to situations where preferences are defined only for a given set of acts, and for lotteries among these and sure consequences (case 2). In this paper, we provide a similar extension for two other situations : those where only the set of optimal elements from a given set of acts is known (case 3); and those where only a single optimal act is known (case 4). To these four cases correspond four nested sets of admissible subjective probabilities over the states or the opponent’s strategies, namely a singleton in case 1 and increasing sets in cases 2-4. The results for case 3 and 4 also define the extent to which subjective probabilities must be specified in order to solve a given decision problem or play a given name.

Kinky perceived demand curves and Keynes-Negishi equilibria

The label “Keynes-Negishi equiibria” is attached here to equilibria in a monetary economy with imperfectly competitive product and labor markets where business firms and labor unions hold demand perceptions with kinks - as posited in Negishi’s 1979 book Microeconomic Foundations of Keynesian Macroeconomics. Such equilibria are defined in a general equilibrium model, and shown to exist. Methodological implications are briefly discussed in a concluding section.Equilibrium, imperfect competition, perceived demands, kinky demand, princing rules, union wage model, union objectives, cash-in-advance

Vountary matching grants can forestall social dumping

The European economic integration leads to increasing mobility of factors, thereby threatening the stability of social transfer programs. This paper investigates the possibility to achieve by means of voluntary matching grants both the optimal allocation of factors and the optimal level of redistribution in the presence of factor mobility. We use a fiscal competition model a la Wildasin (1991) in which states differ in their technologies and preferences for redistribution. We first investigate a simple process in which the regulatory authority progressively raises the matchning grants sto the district choosing the lowest transfer and all districts respond optimally to the resulting change in transfers all around. This process is shown to increase total production and the level of redistribution. However, it does not guarantee that all districts gain, nor that an efficient level of redistribution is attained. Assuming complete information among districts, we first derive the willingness of each district to match the contribution of other districts and we show that the aggregate willingness to pay for matching rates converges to zero when both the efficient level of redistribution and the efficient outcome and guarantee that everyone will gain.Fiscal federalism, Adjustment process, Matching grants

Stock prices, anticipations and investment in general equilibrium

We propose an objective for the firm in a model of production economies extending over time under uncertainty and with incomplete markets. We derive the objective of the firm from the assumption of initial-shareholders efficiency. Each shareholder is assumed to communicate to the firm her marginal valuation of profits at all future events (expressed in terms of initial resources). In defining her own marginal valuation of the firm's profits, a shareholder takes into consideration the direct impact of a change in the value of dividends but also the impact of future dividends on the firm's stock price when she trades shares. To predict the impact on the stock price, she uses a state price process, her price theory. The firm computes its own shadow prices for profits at all date-events by simply adding up the marginal valuations of all its initial shareholders. If no restrictions are placed on individual price theories, the existence of equilibria may require financial constraints on a firm's investment when its shareholders are more optimistic than the market about the profitability of such investment. We then impose that price theories be compatible with the observed equilibrium: they should satisfy a no-arbitrage condition. We show by means of an example that, with incomplete markets and no-short selling constraints, this restriction on price theories is not enough to bring consistency in the individuals' marginal evaluations: a financial constraint on the firm's investment may still be needed to obtain an equilibriumgeneral equilibrium, incomplete markets, stock prices, anticipations, investment constraints, arbitrage

Shareholder-efficient production plans in a multi-period economy

We propose an objective for the firm in a general model of production economies extending over time under uncertainty and with incomplete markets. Trading in commodities and shares of stock occurssequentially on spot markets at all date-events. We derive the objective of the firm from the assumption of initial-shareholders efficiency.Each shareholder is assumed to communicate to the firm her marginal valuation of profits at all date events (expressed in terms of initial resources).In defining her own marginal valuation of the firm’s profits, a shareholder will take two elements into consideration. To evaluatethe direct impact of a change in dividends the shareholder uses her own vector of marginal rates of substitution for revenue across dateevents.In addition, the shareholder will take into account the impact of future dividends on the firm’s stock price when she trades shares. Topredict the effect on the stock price, she uses a (possibly different) state price process, her price theory. The only restriction that we imposeon consumers’ price theories is that they should be compatible with the observed equilibrium: given the equilibrium prices and productionplans, a price theory must satisfy a no-arbitrage condition. The firm computes its own shadow prices for profits at all date-events by simplyadding up the marginal valuations of all its initial shareholders. We prove existence of an equilibrium.

Shareholder-efficient production plans in multi-period economy

We propose an objective for the firm in a general model of production economies extending over time under uncertainty and with incomplete markets. Trading in commodities and shares of stock occurs sequentially on spot markets at all date-events. We derive the objective of the firm from the assumption of initial-shareholders efficiency. Each shareholder is assumed to commnicate to the firm her marginal valuation of profits at all date events (expressed in terms of initial resources). In defining her own marginal valuation of the firm’s profits, a shareholder will take two elements into consideration. To evaluate the direct impact of a change in dividends the shareholder uses her own vector of marginal rates of substitution for revenue across date-events. In addition, the shareholder will take into account the impact of future dividends on the firm’s stock price when she trades shares. To predict the effect on the stock price, she uses a (possibly different) state price process, her price theory. The only restriction that we impose on consumers’ price theories is that they should be compatible with the observed equilibrium : given the equilibrium prices and production plans, a price theory must satisfy a no-arbitrage condition. The firm computes its own shadow prices for profits at all date-events by simply adding up the marginal valuations of all its initial shareholders. We prove existence of an equilibrium.

Investment Stimulation, with Some Reference to Housing

This paper is a follow-up on Section 5 of Drèze, Malinvaud et al.’s 1994 position paper on “Growth and Employment : The Scope for a European Initiative”, in favour of policies aiming to sustain demand through investments, without aggravating public deficits. We build on several recent papers to investigate further the argument. We first briefly review a non-standard theoretical model based upon contemporaneous thinking about incompleteness of markets, and its econometric validation. This analysis suggests that policies aimed at stimulating aggregate activity and supporting more optimistic expectations may be needed to achieve faster growth in economies suffering from persistent underutilistion of resources. We next elaborate on the principle of employment subsidies, with reference to housing. At times of severe unemployment, a correct evaluation of investment projects must take into account the wedge between the private and the social cost of labour. This labour cost distortion generates a discouting distortion. We briefly discuss both and derive implications for investment stimulation policies. We also review the main problems of implementation of a European investment program and report on a preliminary attempt at checking the applicability to housing in Wallony.