A re-examination of the “zero is enough” hypothesis in the emergence of financial stylized facts

In recent years, a growing literature has claimed that the market microstructure is sufficient to generate the so-called stylized facts without any reference to the behaviour of market players. Indeed, qualitative stylized-facts can be generated with zero-intelligence traders (ZITs) but we stress that they are without any quantitative predictive power. In this paper we show that in most of the cases, such qualitative stylized facts hide unrealistic price motions at the intraday level and ill-calibrated return processes as well. To generate realistic price motions and return series with adequate quantitative values is out-of-reach using pure ZIT populations. To do so, one must increasingly constrain agents?? choices to a point where it is hard to claim that their behaviour is completely random. In addition we show that even with highly constrained ZIT agents, one cannot reproduce real time series from these. Except in a few cases, first order moments of ZITs never equal real data ones. We therefore claim that stylized facts produced by means of ZIT agents are useless for financial engineering.     

THE DYNAMIC PROPERTIES OF ALTERNATIVE ASSUMPTIONS ON PRICE ADJUSTMENT IN NEW KEYNESIAN MODELS

This paper presents a classification of the different new Phillips curves existing in the literature as a set of choices based on three assumptions: the choice of the structure of price adjustments (Calvo or Taylor), the presence of backward indexation and the type of price contracts (fixed prices or predetermined prices). The paper suggests study of the dynamic properties of each specification, following different monetary shocks on the growth rate of the money stock. We develop the analytical form of the price dynamics, and we display graphics for the responses of prices, output and inflation. We show that the choice made for each of the three assumptions has a strong influence on the dynamic properties. Notably, the choice of the price structure, while often considered as unimportant, is indeed the most influential choice concerning the dynamic responses of output and inflation.     

Adaptability, productivity, and educational incentives in a matching model

We study the connections between the labour market and the education sector in a matching framework with ex-post wage bargaining. Workers have multidimensional skills and the search market is segmented by technology. Education is a time-consuming activity and determines jointly the scope - or adaptability - and intensity - or productivity - of individual skills. We establish three main results. First, unemployment provides incentives to schooling by raising the need for adaptability. Second, private returns to productivity are below social returns, but no hold-up phenomenon is involved. Third, due to wage and congestion externalities, private returns to adaptability exceed social returns. As a consequence, both over- and under-education may take place in equilibrium.     

Collective consumption and welfare

Abstract.  In this paper, we present a collective model of household demand based on Pareto‐efficiency. In addition, we suppose that (a) each household member is egoistic and consumption is purely private, (b) there is a set of distribution factors and (c) there is one exclusive good. Then we derive the testable restrictions that are implied by this theoretical setting and show how welfare comparisons at the individual level can be performed. JEL classification: D11     

Iterated potential and robustness of equilibria

For any given set-valued solution concept, it is possible to consider iterative elimination of actions outside the solution set. This paper applies such a procedure to define the concept of iterated monotone potential maximizer (iterated MP-maximizer). It is shown that under some monotonicity conditions, an iterated MP-maximizer is robust to incomplete information [A. Kajii, S. Morris, The robustness of equilibria to incomplete information, Econometrica 65 (1997) 1283-1309] and absorbing and globally accessible under perfect foresight dynamics for a small friction [A. Matsui, K. Matsuyama, An approach to equilibrium selection, J. Econ. Theory 65 (1995) 415-434]. Several simple sufficient conditions under which a game has an iterated MP-maximizer are also provided.     

Downstream labeling and upstream price competition

This paper analyses the economic consequences of labeling in a setting with two vertically related markets. Labeling on the downstream market affects upstream price competition through two effects: a differentiation effect and a ranking effect. The magnitude of these two effects determines who in the supply chain will receive the benefits and who will bear the burden of labeling. For instance, whenever the ranking effect dominates the differentiation effect, the low-quality upstream firm loses from labeling while all downstream actors are individually better off. By decreasing the low-quality input price, the label acts as a subsidy and leads to an increase of the downstream market welfare. This analysis furthers our understanding of the economic consequences of labeling in cases like those of GMOs or restaurants.