Ambiguous events and maxmin expected utility

We study the properties associated to various definitions of ambiguity [L.G. Epstein, J. Zhang, Subjective probabilities on subjectively unambiguous events, Econometrica 69 (2001) 265-306; P. Ghirardato et al., Differentiating ambiguity and ambiguity attitude, J. Econ. Theory 118 (2004) 133-173; K. Nehring, Capacities and probabilistic beliefs: a precarious coexistence, Math. Soc. Sci. 38 (1999) 197-213; J. Zhang, Subjective, ambiguity, expected utility and Choquet expected utility, Econ. Theory 20 (2002) 159-181] in the context of Maximin Expected Utility (MEU). We show that each definition of unambiguous events produces certain restrictions on the set of priors, and completely characterize each definition in terms of the properties it imposes on the MEU functional. We apply our results to two open problems. First, in the context of MEU, we show the existence of a fundamental incompatibility between the axiom of “Small unambiguous event continuity” (Epstein and Zhang, 2001) and the notions of unambiguous event due to Zhang (2002) and Epstein and Zhang (2001). Second, we show that, in the context of MEU, the classes of unambiguous events according to either Zhang (2002) or Epstein and Zhang (2001) are always λ-systems. Finally, we reconsider the various definitions in light of our findings, and identify some new objects (Z-filters and EZ-filters) corresponding to properties which, while neglected in the current literature, seem relevant to us.     

Income Inequality and Health: Do the Equivalence Scales Matter?

The aim of this paper is to explore the relationship between income inequality and health in the European Union countries using new data from the European Community Household Panel (ECHP). The heterogeneity of the households has been approached using different equivalence scales. A variety of different model specifications were tried using different dependent variables such as life expectancy at birth and child mortality. The results give support to the influence of income inequality on health indicators using aggregate data and panel techniques, and show the sensitivity of the Gini index to the equivalence scale considered.     

Wage expectations in northern and southern Italian regions: An interpretation based on psychological and social factors

Individual wage expectations of Italian unemployed are studied. The analysis is carried out separately for the North‐Central and southern Italian regions using semiparametric additive models. Results show a marked difference in expectations formation across regions. We argue that as far as the labour market information in the South is less diffuse and more ambiguous than in the North, the divergence between the econometric model based on a utility‐maximisation mainstream theory and the actual wage expectation mechanism may be large. A tentative explanation based on psychological and social factors is offered.     

Corruption and Technological Progress: A Takeoff Theory of Good Governance

Corruption is known to be a function of its return relative to productive activity. But the idea that corruption might itself respond to technological progress has not been emphasized. This paper presents an approach for thinking about institutional features that lower corruption by lowering its relative return. Policies that promote productivity growth in market exchange may cause the relative reward to rent-seeking to decline. The evolutionary development of anti-corruption efforts may be a normal part of modernization, much as changes in income distribution and urbanization.     

Terms of trade risk with partial labor mobility

We examine the welfare consequences of terms-of-trade risk in a small open economy in which it is costly for workers to move between sectors. Relocation costs lead to partial labor mobility, sectoral wage gaps and income risk exceeding that of an economy in which relocation is costless. Using observed wage differentials and standard values for volatility and preferences, we find that the welfare cost of partial labor mobility alone is unlikely to be very large, even in the absence of self-insurance arrangements. In addition, modest consumption substitution elasticities significantly reduce these welfare costs.     

Introduction: Input–Output Analysis of Interindustry R&D Spillovers

As an introduction to this special issue on intersectoral R&D spillovers, I shall first explain what these spillovers are and how economists try to estimate them. I shall then describe the seven papers selected for this issue from the expanding literature on R&D spillovers, summarize their major results and suggest further avenues of research in this area.     

OPTIMAL GROWTH IN A TWO‐SECTOR RSS MODEL WITHOUT DISCOUNTING: A GEOMETRIC INVESTIGATION*

This essay reports results on optimal growth in a two‐sector model with fixed coefficients, irreversible investment and no discounting. Under normalization, the model can be represented by two real numbers, but despite its deceptive simplicity, it admits rich transition dynamics and apparent pathologies that seem to have been missed in earlier work. From a methodological point of view, and in the light of recent work of Nishimura and Yano, this essay can also be seen as a further rehabilitation of geometric methods as an engine of analysis.     

Does Overconfidence Affect Corporate Investment? CEO Overconfidence Measures Revisited

This article presents the growing research area of Behavioural Corporate Finance in the context of one specific example: distortions in corporate investment due to CEO overconfidence. We first review the relevant psychology and experimental evidence on overconfidence. We then summarise the results of Malmendier and Tate (2005a) on the impact of overconfidence on corporate investment. We present supplementary evidence on the relationship between CEOs’ press portrayals and overconfident investment decisions. This alternative approach to measuring overconfidence, developed in Malmendier and Tate (2005b), relies on the perception of outsiders rather than the CEO's own actions. The robustness of the results across such diverse proxies jointly corroborates previous findings and suggests new avenues to measuring executive overconfidence.