provision of information and valuable suggestions. DISCLAIMER: Mention of a trademark, warranty, proprietary product or vendor does not constitute a guarantee by the U. S. Department of Agriculture and does not imply approval or recommendation of the product to the exclusion of others that may be suitable. ABBREVIATIONS: HITs (high impact traits), TM (trade mark), R (Registered), HVI (high volume instrumentation),

Because of sorting, more skilled workers are more productive in higher type firms. They also learn at different rates about their productivity and therefore expect different wage paths across firms. We show that under strict supermodularity there is always positive assortative matching: differential learning is always dominated by the impact of productivity. Surprisingly, this holds even if learning is faster in the low type firm. The key assumption driving this result is that this is a pure Bayesian learning model. We also derive a new equilibrium condition in this class of continuous time models in addition to the common smooth-pasting and valuematching conditions. This no-deviation condition captures sequential rationality and results in a restriction on the second derivative of the value function.

numerous colleagues for their suggestions.

as the Presidential Address to the American Finance Association on January 7, 2006. It reflects the intellectual contributions of colleagues, coauthors, and students too numerous to thank individually. I would like to acknowledge, however, the special influence of my dissertation advisers at Yale

In the mitochondrial pathway of apoptosis, caspase activation is closely linked to mitochondrial outer membrane permeabilization (MOMP). Numerous pro-apoptotic signal-transducing molecules and pathological stimuli converge on mitochondria to induce MOMP. The local regulation and execution of MOMP

conversations with numerous colleagues. We are particularly indebted to

training at the sentence level

We appreciate contributions of numerous colleagues to the refinement and description of this method.

and to return to the annuity market as many times as they wish. Using numerical optimization techniques, assuming the levels of actuarial unfairness of annuities calculated in previous research, and retaining the assumption made in previous research that one half of household wealth is pre-annuitized, we

Milesi-Ferretti, Assaf Razin and numerous other colleagues and seminar participants for comments and helpful discussions and to Sarma Jayanthi for research assistance. The views expressed herein are those of the authors and are not necessarily those of the IMF or the National Bureau of Economic