Efficiency Wages and the Wage Structure

This paper examines differences in pay for equally skilled workers in different industries. The major finding is that there is substantial dispersion in wages across industries, even after allowing for measured and unmeasured labor quality, working conditions, fringe benefits, transitory demand shocks, threat of unionization, union bargaining power, firm size and other factors. Some direct evidence in favor of efficiency wage theories is presented. The evidence suggests that industry wage differentials are successful in eliciting better performance through reduced turnover and increased effort.

Reflections on the Inter-Industry Wage Structure

This paper reviews available evidence on the inter-industry wage structure. The inter-industry wage structure is remarkably similar in different eras, in different countries, and among different types of workers. Industries with high capital-to-labor ratios, monopoly power and high profits pay relatively high wages. We conclude that the competitive model cannot without substantial modification provide an adequate explanation of the inter-industry wage structure. The implications of this finding for micro and macro economic theory and policy are examined.

Correlation of shock initiated and thermally initiated chemical reactions in a 1:1 atomic ratio nickel-silicon mixture

Shock initiated chemical reaction experiments have been performed on a 1:1 atomic ratio mixture of 20- to 45-µm nickel and –325 mesh crystalline silicon powders. It has been observed that no detectable or only minor surface reactions occur between the constituents until a thermal energy threshold is reached, above which the reaction goes to completion. The experiments show the energy difference between virtually no and full reaction is on the order of 5 percent. Differential scanning calorimetery (DSC) of statically pressed powders shows an exothermic reaction beginning at a temperature which decreases with decreasing porosity. Powder, shock compressed to just below the threshold energy, starts to react in the DSC at 621 °C while powder statically pressed to 23% porosity starts to react at about 30 °C higher. Tap density powder starts to react at 891 °C. The DSC reaction initiation temperature of the shock compressed but unreacted powder corresponds to a thermal energy in the powder of 382 J/g which agrees well with the thermal energy produced by a shock wave with the threshold energy (between 384 and 396 J/g). (Thermal energies referenced to 20 °C.) A sharp energy threshold and a direct correlation with DSC results indicates that the mean thermal energy determines whether or not the reaction will propagate in the elemental Ni+Si powder mixture rather than local, particle level conditions. From this it may be concluded that the reaction occurs on a time scale greater than the time constant for thermal diffusion into the particle interiors

Demographic Change, Relative Factor Prices, International Capital Flows, and Their Differential Effects on the Welfare of Generations

Demographic change has differential impacts on the welfare of current and future generations. In a simple closed economy, aging -- a relative scarcity of young workers -- increases wages, increasing the welfare of the young. At the same time, population aging will reduce rates of return to capital, thereby reducing the welfare of asset holders who are usually older than the population average. In a global world with pension systems, however, these effects are less straightforward, since international capital flows dampen the factor price changes. Moreover, pay-as-you-go pension systems financed by payroll taxes create a wedge between net and gross wages, and their intergenerational redistribution has important additional effects on the welfare of generations. To quantify these effects, we develop a large-scale multi-country overlapping generations model with uninsurable labor productivity and mortality risk. Due to the predicted relative abundance of the factor capital, the rate of return falls between 2005 and 2050 by roughly 90 basis points. Our simulations indicate that capital flows from rapidly ageing regions to the rest of the world will initially be substantial, but that trends are reversed when households de-cumulate savings. In terms of welfare, our model suggests that young individuals with little assets and currently low labor productivity indeed gain from higher wages associated with population aging. Older, asset-rich households tend to loose because of the predicted decline in real returns to capital.

The local dust foregrounds in the microwave sky: I. Thermal emission spectra

Analyses of the cosmic microwave background (CMB) radiation maps made by the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed anomalies not predicted by the standard inflationary cosmology. In particular, the power of the quadrupole moment of the CMB fluctuations is remarkably low, and the quadrupole and octopole moments are aligned mutually and with the geometry of the Solar system. It has been suggested in the literature that microwave sky pollution by an unidentified dust cloud in the vicinity of the Solar system may be the cause for these anomalies. In this paper, we simulate the thermal emission by clouds of spherical homogeneous particles of several materials. Spectral constraints from the WMAP multi-wavelength data and earlier infrared observations on the hypothetical dust cloud are used to determine the dust cloud's physical characteristics. In order for its emissivity to demonstrate a flat, CMB-like wavelength dependence over the WMAP wavelengths (3 through 14 mm), and to be invisible in the infrared light, its particles must be macroscopic. Silicate spheres from several millimetres in size and carbonaceous particles an order of magnitude smaller will suffice. According to our estimates of the abundance of such particles in the Zodiacal cloud and trans-neptunian belt, yielding the optical depths of the order of 1E-7 for each cloud, the Solar-system dust can well contribute 10 microKelvin (within an order of magnitude) in the microwaves. This is not only intriguingly close to the magnitude of the anomalies (about 30 microKelvin), but also alarmingly above the presently believed magnitude of systematic biases of the WMAP results (below 5 microKelvin) and, to an even greater degree, of the future missions with higher sensitivities, e.g. PLANCK.Comment: 33 pages, 9 figures, 1 table. The Astrophysical Journal, 2009, accepte

The formation of 3,6-diphenylpyridazine and 2,5-diphenylpyrrole from alpha-styryl azide

Formation of 3,6-diphenylpyridazine and 2,5- diphenylpyrrole from alpha-styryl azid

Acid catalyzed reactions of alpha and beta styryl azides

Acid degradation of alpha and beta styryl azide

Variation in the four-spined stickleback.

Thesis (M.A.)--Boston UniversityThe four-spined stickleback shows a variation of 30-33 vertebrae, 9-14 dorsal fin rays, 7-ll anal fin rays, and 2-6 dorsal spines. No correlation exists between any of the characters except dorsal and anal rays, which are strongly correlated. Vertebrae show a sligltt tendency to decrease in number from north to south, while dorsal and anal rays and dorsal spines vary irregularly throughout the range of the species, with no significant difference between populations at either end of the range. Individual differences, however, are sufficient to divide the species into subspecies and races, using the criteria of modern taxonomists. But the presence of clines, plus the fact, that between any two populations, no matter how divergent, intergrading populations can be found throughout the range of the species, suggests that the variation encountered may be environmental and not genetic. Numerous field and experimental studies, reported in the literature, have revealed many different and often contrasting correlations between environmental factors and meristic characters. Taning (1952) showed that each meristic character in Salmo trutta has its own phenocritical period, and was able to produce a range in means of 3.2 vertebrae in offspring of the same parents by varying the temperature during the phenocritical period. The phenocritical period for anal rays was found to overlap slightly with that of the vertebrae, while dorsal and pectoral rays are determined much later. Taning found that vertebrae, and in part anal rays, are mainly determined genotypically, while dorsal and pectoral rays are determined phenotypically. Heuts (1947) showed that there exists in the European stickleback, Gasterosteus aculeatus, the phenomenon of two adaptive peaks. Natural selection favors those individuals with low mean plate numbers in waters of low salinity, and those with high mean plate numbers at high salinities. Heuts (1949) found that fin ray numbers in both types are similarly modifiable by temperature within their own respective habitats. The findings of Taning and Heuts may help to explain the pattern of variation in Apeltes quadracus. The variation encountered in mean vertebral numbers may be due to the temperature lability of a single genotype, indicating that no intraspecific categories should be recognized. Since dorsal and anal rays are correlated with each other but not with vertebrae or spines, they probably develop at about the same time in ontogeny and may be highly modifiable by temperature. As spines show no correlation with the other characters considered, a different explanation for their variation is offered. Cox (1923) found a distinct correlation between spine number and salinity in Apeltes quadracus in the Maritime Provinces. I have found a similar, though imperfect correlation in several localities, with four-spined individuals more abundant at high salinities, and five-spined individuals predominant at low salinities. A selective mechanism similar to the one described by Heuts is believed responsible, with many-spined individuals being selected for at low salinities, and fewer-spined individuals being favored at high salinities. The explanations offered here are conjectural, and alternatives could be given. Only further study, especially experimental work, may fully explain the variation in Apeltes quadracus. [TRUNCATED