Changes in Relative Wages, 1963-1987: Supply and Demand Factors

A simple supply and demand framework is used to analyze changes in the U.S. wage structure from 1963 to 1987. Rapid secular growth in the demand for more-educated workers, 'more-skilled' workers, and females appears to be the driving force behind observed changes in the wage structure. Measured changes in the allocation of labor between industries and occupations strongly favored college graduates and females throughout the period. Movements in the college wage premium over this period appear to be strongly related to fluctuations in the rate of growth of the supply of college graduates.

Are Efficiency Wages Efficient?

Efficiency wage models have been criticized because worker malfeasance can be prevented in a pareto efficient manner by requiring workers to post a bond which they lose if they are caught cheating. However, since it is costly to monitor workers and costless to demand a larger bond, firms should pay nothing for monitoring and demand very large bonds. Since we observe that firms devote considerable resources to monitoring workers, bonds must be limited. Therefore firms must use second best alternatives -- intensive monitoring and/or efficiency wages. The payment of efficiency wages cannot be ruled out on a priori theoretical grounds.

The influence of accommodation and fixation on the visual evoked response and visual acuity of normal and amblyiopic subjects

Twelve normal and twelve amblyopic subjects were examined to investigate the differences in visual evoked response (VER) as well as the state and influence of the accommodative posture and accommodative response on the VER and visual acuity. The VER amplitudes were shown to be lower in the amblyopic eye a significant proportion of the time, while the implicit times were not significantly different. The accommodative system of the amblyope was shown to differ in both eyes from that of the normal subject, with the amblyopic eye also hypoposturing in comparison to the normal eye of the amblyope. This did not affect the VER or visual acuity significantly. The degree of eccentric fixation had no statistically significant relationship to the VER, accommodative, or visual acuity data. The VER, Haidinger brushes and Maxwell spot were in close agreement for differentiating organic from functional amblyopia

Employee Crime and the Monitoring Puzzle

The simplest economic theories of crime predict that profit-maximizing firms should follow strategies of minimal monitoring with large penalties for employee crime. We investigate possible reasons why firms actually spend considerable resources trying to detect employee malfeasance. We find that the most plausible explanations for firms' large outlays on monitoring of employees-legal restrictions on penalty clauses in contracts and the adverse impact of harsh punishment schemes on worker morale-are also consistent with the payment of premium (rent-generating) wages by cost-minimizing firms.Economic

Increasing the sensitivity of hyperpolarized [15 N2 ]urea detection by serial transfer of polarization to spin-coupled protons.

PURPOSE: Hyperpolarized 15 N-labeled molecules have been proposed as imaging agents for investigating tissue perfusion and pH. However, the sensitivity of direct 15 N detection is limited by the isotope's low gyromagnetic ratio. Sensitivity can be increased by transferring 15 N hyperpolarization to spin-coupled protons provided that there is not significant polarization loss during transfer. However, complete polarization transfer would limit the temporal window for imaging to the order of the proton T1 (2-3 s). To exploit the long T1 offered by storing polarization in 15 N and the higher sensitivity of 1 H detection, we have developed a pulse sequence for partial polarization transfer. METHODS: A polarization transfer pulse sequence was modified to allow partial polarization transfer, as is required for dynamic measurements, and that can be implemented with inhomogeneous B1 fields, as is often the case in vivo. The sequence was demonstrated with dynamic spectroscopy and imaging measurements with [15 N2 ]urea. RESULTS: When compared to direct 15 N detection, the sequence increased the signal-to-noise ratio (SNR) by a factor of 1.72 ± 0.25, where both experiments depleted ~20% of the hyperpolarization (>10-fold when 100% of the hyperpolarization is used). Simulations with measured cross relaxation rates showed that this sequence gave up to a 50-fold increase in urea proton polarization when compared to spontaneous polarization transfer via cross relaxation. CONCLUSION: The sequence gave an SNR increase that was close to the theoretical limit and can give a significant SNR benefit when compared to direct 13 C detection of hyperpolarized [13 C]urea

The Changing Role of RSEs over the Lifetime of Parsl

This position paper describes the Parsl open source research software project and its various phases over seven years. It defines four types of research software engineers (RSEs) who have been important to the project in those phases; we believe this is also applicable to other research software projects.Comment: 3 page