Explaining the rising concentration of banking assets in the 1990s

In recent years, the nation's largest bank holding companies have sharply increased their market share of assets. Have these institutions achieved their dominance by expanding their existing subsidiaries or by merging with other bank holding companies? A study of industry data for 1990-99 suggests that the increased market share of the largest companies is attributable almost entirely to external growth through mergers and acquisitions.Bank assets ; Bank holding companies ; Bank mergers

Sources of Unreliable Testimony from Children

We distilled research findings on sources of unreliable testimony from children into four principles that capture how the field of forensic developmental psychology conceptualizes this topic. The studies selected to illustrate these principles address three major questions: (a) how do young children perform in eyewitness studies, (b) why are some children less accurate than others, and (c) what phenomena generate unreliable testimony? Throughout our research, our focus is on factors other than lying that produce inaccurate or seemingly inconsistent autobiographical reports.Collectively, this research has shown that (a) children’s eyewitness accuracy is highly dependent on context, (b) neurological immaturity makes children vulnerable to errors under some circumstances, and (c) some children are more swayed by external influences than others. Finally, the diversity of factors that can influence the reliability of children’s testimony dictates that (d) analyzing children’s testimony as if they were adults (i.e., with adult abilities, sensibilities, and motivations) will lead to frequent misunderstandings. It takes considerable knowledge of development—including information about developmental psycholinguistics, memory development, and the gradual emergence of cognitive control—to work with child witnesses and to analyze cases as there are many sources of unreliable testimony

Microstrip resonator for microwaves with controllable polarization

In this work the authors implemented a resonator based upon microstrip cavities that permits the generation of microwaves with arbitrary polarization. Design, simulation, and implementation of the resonators were performed using standard printed circuit boards. The electric field distribution was mapped using a scanning probe cavity perturbation technique. Electron spin resonance using a standard marker was carried out in order to verify the polarization control from linear to circular.Comment: 3 pages, 3 figures, submitted to Appl. Phys. Let

Wage Effects of Trade Reform with Endogenous Worker Mobility

In this paper, we use a linked employer–employee database from Brazil to evaluate the wage effects of trade reform. With an aggregate (firm-level) analysis of this question, we find that a decline in trade protection is associated with an increase in average wages in exporting firms relative to domestic firms, consistent with earlier studies. However, using disaggregated, employer-employee level data, and allowing for the endogenous assignment of workers to firms due to match-specific productivity, we find that the premium paid to workers at exporting firms is economically and statistically insignificant, as is the differential impact of trade openness on the wages of workers at exporting firms relative to otherwise identical workers at domestic firms. We also find that workforce composition improves systematically in exporting firms, in terms of the combination of worker ability and the quality of worker-firm matches, post-liberalization. These results stand in stark contrast to the findings reported in many earlier studies and underscore the importance of endogenous matching and, more generally, non-random labor market allocation mechanisms, in determining the effects of trade policy changes on wages.