Progress toward a first observation of parity violation in chiral molecules by high-resolution laser spectroscopy

Parity violation (PV) effects in chiral molecules have so far never been experimentally observed. To take this challenge up, a consortium of physicists, chemists, theoreticians and spectroscopists has been established and aims at measuring PV energy differences between two enantiomers by using high-resolution laser spectroscopy. In this article, we present our common strategy to reach this goal, the progress accomplished in the diverse areas, and point out directions for future PV observations. The work of Andr\'e Collet on bromochlorofluoromethane enantiomers, their synthesis and their chiral recognition by cryptophanes made feasible the first generation of experiments presented in this paper.Comment: 30 pages, 11 figure

A Model of Asymmetric Employer Learning with Testable Implications

This paper helps close the gap between theory and empirical evidence in the literature on asymmetric employer learning. If an employer's private learning is reflected in a worker's wage and one employer's private information is transmitted to the next when the worker makes a job-to-job transition, then asymmetric employer learning will appear in wage regressions as learning over an employment spell. Extending previous work that assumes all learning takes place publicly, this paper develops wage regressions that test for both asymmetric employer learning and public learning. The empirical results, including tests of alternative explanations, are consistent with asymmetric employer learning's having at least as much of an effect on wages during an employment spell as does public learning. The model developed in this paper illustrates how the story suggested by the empirical work might unfold. It shows that outside firms can profitably compete with a better-informed employer through bidding wars, even when the worker is equally productive in all firms. Furthermore, this competition results in different wages for workers with the same publicly observable characteristics, a result that previous models of asymmetric learning have not produced. Copyright © 2009 The Review of Economic Studies Limited.

Entry and Strategic Information Display in Credit Markets

In many countries, lenders voluntarily provide information about their borrowers to private credit registries. A recent World Bank survey reveals that the display of a lender's own borrower information is often not reciprocated. That is, access to these registries does not require the prior provision of proprietary data. We argue that incumbent lenders release information about a portion of their profitable borrowers for strategic reasons. The reasoning is that the pool of unreleased borrowers becomes characterised by a severe adverse selection problem. This prevents the entrants from bidding for all the incumbent's profitable borrowers and reduces their scale of entry. Copyright 2006 The Authors. Journal compilation Royal Economic Society 2006.