An Asymmetric Kalai-Smorodinsky Solution

In 1972, Harsanyi and Selten characterized a one parameter asymmetric Nash solution. In this note I do the analog for the Kalai-Smorodinsky solution. By dropping symmetry and adding a restrivted version of Independence of Irrelevant Alternatives to the set of axioms that lead to the Kalai-Smorodinsky solution, I characterize an asymmetric version of that solution concept that depends only on one parameter.BARGAINING

Overconfidence in Search

In a standard search model I relax the assumption that agents know the distribution of offers and characterize the behavioral and welfare consequences of overconfidence. Optimistic individuals search longer if they are equally stubborn and high offers are good news. Otherwise, the pessimists search longer. The welfare of unbiased individuals is larger than that of overconfident decision makers if the latter's biases are large and searchers stubborn. Otherwise, the overconfident may be better off. Finally, I give a testable implication of overconfidence and discuss applications and policy issues.

Interview with Kenneth Arrow

Arrow argues that the biggest failures of economic theory are: our failure to explain the business cycle; the missing explanations for the size of fluctuations of prices; our failure to explain the causes of growth and of the spread of innovation. He then discusses several of the existing alternatives to the rational expectations paradigm. He tells the story of his dissertation, and how Koopmans wanted to decline his Nobel Prize.Finally, he discusses health care reform, and malaria in Africa.Health Care; Business Cycles; Fluctuations

A Correction to Uniqueness in 'Competitive Bidding and Proprietary Information'

In this note I show that there is a mistake in the proof of uniqueness in Engelbrecht-Wiggans, Milgrom and Weber’s seminal “Competitive Bidding and Proprietary Information” and provide a correct proof.Auctions, Uniqueness, Asymmetric Information

Asymmetric English Auctions Revisited

I introduce a property of player's valuations that ensures the existence of an ex post efficient equilibrium in asymmetric English auctions. The use of this property has the advantage of yielding an ex post efficient equilibrium without assuming differentiability of valuations or that signals are drawn from a density. These technical, non economic, assumptions have been ubiquitous in the study of (potentially) asymmetric English auctions. Therefore, my work highlights the economic content of what it takes to obtain efficient ex post equilibria. I generalize prior work by Echenique and Manelli (2006) and by Birulin and Izmalkov (2003). Relative to Krishna (2003), I weaken his single crossing properties, drop his differentiability and densities assumptions, but I assume that one player's valuation is weakly increasing in other players' signals, while he uses a different assumption (neither stronger nor weaker).Efficiency; English Auctions; ex-post equilibrium

Monotone Preferences over Information

We consider preference relations over information that are monotone: more information is preferred to less. We prove that, if a preference relation on information about an uncountable set of states of nature is monotone, then it is not representable by a utility function

Information is not about measurability

We present a simple example where the use of σ-algebras as a model of information leads to a paradoxical conclusion: a decisionmaker prefers less information to more. We then explain that the problem arises because the use of σ-algebras as the informational content of a signal is inadequate. We provide a characterization of the different models of information in the literature in terms of Blackwell’s theorem

The problem of prevention

Many disasters are foreshadowed by insufficient preventative care. In this paper, we argue that there is a true problem of prevention, in that insufficient care is often the result of rational calculations on the part of agents. We identify three factors that lead to dubious efforts in care. First, when objective risks of a disaster are poorly understood, positive experiences may lead to an underestimation of these risks and a corresponding underinvestment in prevention. Second, redundancies designed for safety may lead agents to take substandard care. Finally, elected officials have an incentive to underinvest in prevention for some disasters, especially those that are relatively unlikely

First-order Design of a Reflective Viewfinder for Adaptive Optics Ophthalmoscopy

Adaptive optics (AO) ophthalmoscopes with small fields of view have limited clinical utility. We propose to address this problem in reflective instruments by incorporating a viewfinder pupil relay designed by considering pupil and image centering and conjugation. Diverting light from an existing pupil optical relay to the viewfinder relay allows switching field of view size. Design methods that meet all four centering and conjugation conditions using either a single concave mirror or with two concave mirrors forming an off-axis afocal telescope are presented. Two different methods for calculating the focal length and orientation of the concave mirrors in the afocal viewfinder relay are introduced. Finally, a 2.2 × viewfinder mode is demonstrated in an AO scanning light ophthalmoscope

Adaptive Optics Scanning Ophthalmoscopy with Annular Pupils

Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections