Jan Tuinstra

Coordination of Expectations in Asset Pricing Experiments

An information display device wherein there is a base plate with information bearing face plates detachably mounted thereon by one or more spline elements that press-fit with formations on each of the opposing faces of the base and face plate. End caps are optional as are also separator strips between panels where there are a number of panels mounted on one base plate. Splines press-fit into grooves in each of the base plate and face plate. In one embodiment the spline is U-shaped receiving therein a rib on one member and projecting into a groove formed between two ribs on the other of the two plates.

Identification of Voters with Interest Groups Improves the Electoral Chances of the Challenger

This short paper investigates the consequences of voters identifying with special interest groups in a spatial model of electoral competition. We show that by effectively coordinating voting behavior, identification with interest groups leads to an increase in the size of the winning set, that is, the set of policy platforms for the challenger that will defeat the incumbent. Consequently, our paper points at a novel process through which interest groups can enhance the electoral chances of a challenger.

A price adjustment process in a model of monopolistic competition

Disclosed are devices and methods for performing an assay which determines the presence or quantity of an analyte in a fluid sample by detecting binding of the analyte to at least one immobilized analyte capture reagent and washing unbound material from the immobilized analyte capture reagent. The devices and methods an elongated solid phase flow matrix, including capillary channels capable of driving capillary fluid movement, and further including (i) a first region adapted for receipt of the fluid sample, (ii) a second region at which the analyte capture reagent is immobilized, (iii) a third region for application of a wash reagent capable of removing unbound substances from the second region; and (iv) an absorbent reservoir of high volume capacity. The second region is positioned intermediate to the first region and the third region and intermediate to the absorbent reservoir and the third region. The device also includes means to detect analyte bound at the second region. The flow matrix and the regions thereof are sized and positioned to cause the fluid sample to flow initially along the elongated flow matrix in one direction toward and through the second region, and subsequently, the liquid reagent to flow along the elongated flow matrix in a second direction opposite the first direction, through the second region, and into the absorbent reservoir, drawing unbound substances with it.

Beliefs equilibria in an overlapping generations model

We consider a standard two generations version of the overlapping generations model. Agents predict inflation rates on the basis of a perceived law of motion, which is estimated by running a linear regression on past inflation rates. We introduce the notion of beliefs equilibrium. At such an equilibrium: (i) the perceived law of motion is such that it fits the time series of inflation rates best, and (ii) this time series of actual inflation rates is generated when agents use that perceived law of motion. We show that beliefs might converge, although inflation rates keep on fluctuating. These fluctuations are consistent with the limit belief.

A discrete and symmetric price adjustment process on the simplex

Abstract We study the tâtonnement process in an exchange economy with three commodities and three agents. We argue that for the multiplicative tâtonnement process the simplex is a natural normalization rule. We analyse the influence of symmetry in preferences and endowments on the dynamics of the tâtonnement process. Depending on this symmetry there are different bifurcation routes to chaos. In particular, coexisting attractors may emerge when the symmetric equilibrium price vector becomes unstable. This coexistence of attractors is robust in the sense that it also exists for close-by asymmetric tâtonnement processes.

On the equivalence between the overlapping-generations model and cyclical general-equilibrium models

We show that equilibrium cycles in an overlapping-generations model are equivalent to asymmetric equilibria in a general-equilibrium model. We use this equivalence to find equilibrium cycles in the overlapping-generations model with two and three generations, respectively. For the example with two generations we show that for certain parameter values cycles of all periods occur.

Quantifying the Scope for Efficiency Defense in Merger Control: The Werden-Froeb-Index

This paper introduces the Werden-Froeb Index (WFI) to assist in evaluating merger-specific efficiencies in horizontal mergers. The index measures the weighted average reduction in marginal costs required to restore pre-merger equilibrium prices and quantities after the (full or partial) merger is consummated. The WFI is well defined, objective and robust, and it has relatively low information requirements. We propose to use the index as a natural complement to concentration measures such as the Hirschmann-Herfindahl Index in the assessment of horizontal mergers.

Convergence of Bayesian learning to general equilibrium in mis-specified models

Abstract A central unanswered question in economic theory is that of price formation in disequilibrium. This paper lays the groundwork for a model that has been suggested as an answer to this question in, particularly, Arrow [Toward a theory of price adjustment, in: M. Abramovitz, et al. (Ed.), The Allocation of Economic Resources, Stanford University Press, Stanford, 1959], Fisher [Disequilibrium Foundations of Equilibrium Economics, Cambridge University Press, Cambridge, 1983] and Hahn [Information dynamics and equilibrium, in: F. Hahn (Ed.), The Economics of Missing Markets, Information, and Games, Clarendon Press, Oxford, 1989]. We consider sellers that monopolistically compete in prices but have incomplete information about the structure of the market they face. They each entertain a simple demand conjecture in which sales are perceived to depend on the own price only, and set prices to maximize expected profits. Prior beliefs on the parameters of conjectured demand are updated into posterior beliefs upon each observation of sales at proposed prices, using Bayes’ rule. The rational learning process, thus, constructed drives the price dynamics of the model. Its properties are analysed. Moreover, a sufficient condition is provided, relating objectively possible events and subjective beliefs, under which the price process is globally stable on a conjectural equilibrium for almost all objectively possible developments of history.

A Computational Electoral Competition Model with Social Clustering and Endogenous Interest Groups as Information Brokers

We extend the basic model of spatial competition in two directions. First, political parties and voters do not have complete information but behave adaptively. Political parties use polls to search for policy platforms that maximize the probability of winning an election and the voting decision of voters is influenced by social interaction. Second, we allow for the emergence of interest groups. These interest groups transmit information about voter preferences to the political parties, and they coordinate voting behavior. We use simulation methods to investigate the convergence properties of this model. We find that the introduction of social dynamics and interest groups increases the separation between parties platforms, prohibits convergence to the center of the distribution of voter preferences, and increases the size of the winning set.

The emergence of political business cycles in a two-sector general equilibrium model

Abstract We study a simple general equilibrium model with two sectors and two political parties, where each party represents the agents working in one of the sectors. The size of the sectors is endogenous since the government can set a minimum wage in one of the sectors. It is shown that there may be a continuum of political–economic equilibria, and that endogenous political business cycles can emerge.