More on immigrants' earnings over time

Immigrants' earnings have been found to be below those of natives in the earliest years after immigration, but with time in the US, earnings catch up with and then surpass those of natives. The authors obtain this result using an alternate data set, confirming the previous work of Barry Chiswick. The catch up period is between 20 and 30 years, later than Chiswick's result. After adding variables for foreign education and English ability, the catch up period is only 3 years after entry. In a context where other variables are not held constant, the authors consider effects of discrimination in admission by schooling and age. Both are found to be powerful selection factors in increasing the earnings levels of immigrants.

On the optimum theoretical rate of population growth

"The paper seeks intuitively-satisfying models of optimum population growth. The authors build upon Phelps's model of endogenous technical progress plus the Steinmann-Simon extension, which imply that the per-person consumption growth rate depends positively and linearly upon the population growth rate, without bound.... They suggest that the consumption rate ultimately turns downwards as population growth increases because of decreasing adoption of available technology as labor cheapens relative to capital, and as high population growth overtaxes people's will and ability to respond. Including a convex-downward function in the model yields sensible results." (summary in GER)

The effect of immigrants on natives' incomes through the use of capital

"This paper deals with questions about the effects of immigrants on three types of capital: the private capital immigrants work with, the public (government) capital that immigrant workers use, and the public capital used for services by immigrants." The geographic focus is on the United States. The authors conclude that although the average cost to natives in 1975 dollars to provide services for immigrants is 4,172 dollars, this amount "is considerably smaller than the benefits of immigrants to natives through their relatively low use of welfare services and their relatively high contribution of taxes." Comments by Jacob Mincer (pp. 95-7) are included.

There is no low-level fertility and development trap

Summary The theory of the low-level equilibrium trap asserts that an increase in income stimulates population growth sufficiently so that the additional people 'eat up' the 'surplus' over subsistence, and hence drive the level of income back to subsistence. Originally the theory referred primarily to mortality, but nowadays its application is to fertility. In the long-run equilibrium context in which the theory is ordinarily presented, the fact that the long-run elasticity of fertility with respect to income is negative in less developed countries fatally contradicts the accepted version of the trap. But to give every chance for trap theory to be meaningful, the paper presents a period-by-period analysis, embodying larger-than-observed positive elasticities during the early years and the logically necessary counterbalancing negative elasticities during the later years. These elasticities are combined with consumption and production figures for various age groups to estimate the effect in each year after the windfall, and altogether. The results show that even under assumptions not charitable to the conclusion of this paper, additional children do not even come close to 'eating up' the increase in income which induced their births, so that the trap theory is falsified.

Resources, population, environment: an oversupply of false bad news

False bad news about population growth, natural resources, and the environment is published widely in the face of contradictory evidence. For example, the world supply of arable land has actually been increasing, the scarcity of natural resources including food and energy has been decreasing, and basic measures of U.S. environmental quality show positive trends. The aggregate data show no long-run negative effect of population growth upon the standard of living. Models that embody forces omitted in the past, especially the influence of population size upon productivity increase, suggest a long-run positive effect of additional people.

Puzzles and further explorations in the interrelationships of successive births with husband's income, spouses' education and race

When fertility is examined in the detail of individual parity progressions and birth-order transitions, important interactions between the effects of income and education are seen. Among the findings are: the negative effect of education on fertility is stronger at all parities for less educated compared to more highly educated women. Additional income has a more positive effect for more highly educated than for less educated women. For women with 0-8 years of education the effect of more income is positive when the family has no children but negative thereafter, but for college-educated women the effect of more income is positive. And additional income has a less positive (more negative) effect on fertility among nonwhites than among whites.

The welfare effect of an additional child cannot be stated simply and unequivocally

There is no single calculable welfare effect of an additional person. Rather, there are many different judgments, which may be negative or positive. The welfare effect depends upon the particular economic situation the child will be born into, which point in his life-cycle one refers to, whether he is expected to have a positive effect upon his particular sort of economy and society during and after his lifetime, and most of all, on the kind of welfare criterion used. Furthermore, no matter which welfare criterion is used, the welfare effect of an added individual summarized over time is especially sensitive to the particular assumptions made.

Multiple cerebral abscesses complicating hepatopulmonary amebiasis

A 3-year-old boy with hepatopulmonary amebiasis treated with chloroquine phosphate for 20 days subsequently was found to have three brain abscesses and responded to prolonged combined therapy with metronidazole and chloroquine phosphate. Cerebral amebiasis should be considered in any patient with amebic dysentery, hepatic abscess, or pulmonary involvement in whom signs or symptoms of central nervous system involvement appear. A prolonged course of appropriate therapy with periodic brain scanning for evidence of improvement is suggested.