What explains trends in labor force participation of older men in the United States?

After nearly a full century of decline, the Labor Force Participation Rate (LFPR) of older men in the United States leveled off in the 1980s, and began to increase in the late 1990s. We use a time series of cross sections from 1962 to 2005 to model the LFPR of men aged 55-69, with the aim of explaining these trends. We investigate the effects of changes in Social Security rules, lifetime earnings, pension coverage, wages, health, health insurance, and the educational composition of the labor force. Our results indicate that the decline in the LFPR from the 1960s through the 1980s cannot be explained by any of these factors. The recent increase in the LFPR of older men can be explained by changes in the composition of the older male population away from high school dropouts and toward college attendees and graduates. Changes in Social Security may have contributed to the recent increase as well, but the results for Social Security are sensitive to specification

Dislocations and melting in two dimensions: The critical region

A new analysis is presented of the critical-point behavior of two-dimensional melting in the Kosterlitz-Thouless-Nelson-Halperin-Young theory. The analysis confirms the Kosterlitz-Thouless-Nelson-Halperin-Young critical-point exponent, ν̅=0.36963…, but also gives a criterion for its own range of validity amounting to t>10^13 lattice spacings. The implications of these results for experimental verification are discussed

Enhanced heat capacity and a new temperature instability in superfluid He-4 in the presence of a constant heat flux near T-lambda

We present the first experimental evidence that the heat capacity of superfluid 4He, at temperatures very close to the lambda point Tλ, is enhanced by a constant heat flux Q. The heat capacity at constant Q, CQ, is predicted to diverge at a temperature Tc(Q)<Tλ at which superflow becomes unstable. In agreement with previous measurements, we find that dissipation enters our cell at a temperature, TDAS(Q), below the theoretical value, Tc(Q). We argue that TDAS(Q) can be accounted for by a temperature instability at the cell wall, and is therefore distinct from Tc(Q). The excess heat capacity we measure has the predicted scaling behavior as a function of T and Q, but it is much larger than predicted by current theory

Customer experience management in retailing: Understanding the buying process

Abstract Retailers recognize that greater understanding of customers can enhance customer satisfaction and retail performance. This article seeks to enrich this understanding by providing an overview of existing consumer behavior literature and suggesting that specific elements of consumer behavior-goals, schema, information processing, memory, involvement, attitudes, affective processing, atmospherics, and consumer attributions and choices-play important roles during various stages of the consumer decision process. The authors suggest ways in which retailers can leverage this understanding of consumer behavior. Each of these conceptual areas also offers avenues for further research. © 2008 New York University. Published by Elsevier Inc. All rights reserved. Keywords: Consumer behavior; Postpurchase; Goals; Information search; Retail environment; Attribution theory; Attitudes; Affect and mood; Involvement; Attitudes; Decision process The importance of understanding consumer behavior has never been more important to retailers. Whereas consumer research once was a task left to manufacturers of consumer packaged goods, retailers have embraced this responsibility, spending millions of dollars to research, understand, and influence consumer behavior. As we outline, academic research confirms the importance of such practices and we summarize the results of those efforts. Further, this paper develops an ongoing consumer research agenda that provides the authors&apos; views as to the most important consumer issues worthy of retailers&apos; attention. As theoretical work in consumer behavior becomes more refined, retailing must keep pace and remain vigilant in the pur- * Corresponding author. Tel.: +1 617 373 4812

Criticality and Superfluidity in liquid He-4 under Nonequilibrium Conditions

We review a striking array of recent experiments, and their theoretical interpretations, on the superfluid transition in $^4$He in the presence of a heat flux, $Q$. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If $Q$ is in the same direction as gravity, a self-organized state can arise, in which the entire sample has a uniform reduced temperature, on either the normal or superfluid side of the transition. Finally, we review recent theory and experiment regarding the heat capacity at constant $Q$. The excitement that surrounds this field arises from the fact that advanced thermometry and the future availability of a microgravity experimental platform aboard the International Space Station will soon open to experimental exploration decades of reduced temperature that were previously inaccessible.Comment: 16 pages, 9 figures, plus harvard.sty style file for references Accepted for publication in Colloquia section of Reviews of Modern Physic

Multiple origins, one evolutionary trajectory: gradual evolution characterizes distinct lineages of allotetraploid "Brachypodium"

The “genomic shock” hypothesis posits that unusual challenges to genome integrity such as whole genome duplication may induce chaotic genome restructuring. Decades of research on polyploid genomes have revealed that this is often, but not always the case. While some polyploids show major chromosomal rearrangements and derepression of transposable elements in the immediate aftermath of whole genome duplication, others do not. Nonetheless, all polyploids show gradual diploidization over evolutionary time. To evaluate these hypotheses, we produced a chromosome-scale reference genome for the natural allotetraploid grass Brachypodium hybridum, accession “Bhyb26.” We compared 2 independently derived accessions of B. hybridum and their deeply diverged diploid progenitor species Brachypodium stacei and Brachypodium distachyon. The 2 B. hybridum lineages provide a natural timecourse in genome evolution because one formed 1.4 million years ago, and the other formed 140 thousand years ago. The genome of the older lineage reveals signs of gradual post-whole genome duplication genome evolution including minor gene loss and genome rearrangement that are missing from the younger lineage. In neither B. hybridum lineage do we find signs of homeologous recombination or pronounced transposable element activation, though we find evidence supporting steady post-whole genome duplication transposable element activity in the older lineage. Gene loss in the older lineage was slightly biased toward 1 subgenome, but genome dominance was not observed at the transcriptomic level. We propose that relaxed selection, rather than an abrupt genomic shock, drives evolutionary novelty in B. hybridum, and that the progenitor species’ similarity in transposable element load may account for the subtlety of the observed genome dominance