This paper investigates the effect of family size and birth order on educational attainment. An instrumental variables approach is used to identify the effect of family size. Instruments for the number of children are twins at last birth and the sex mix of the first two children. The effect of birth order is identified, by examining the relation…

How much do returns to education differ across different natural experiment methods? To test this, we estimate the rate of return to schooling in Australia using two different instruments for schooling: month of birth and changes in compulsory schooling laws. With annual pre-tax income as our measure of income, we find that the naive ordinary…

Using a new twins sample, presents new estimates of schooling returns and "ability" bias and tests that bias's significance. Ability bias may exist even if ability's genetically-endowed component does not affect schooling decisions directly when correlated with other family characteristics (like income) that do affect schooling. (19…

Uses data from a sample of New Zealand twins to test the relationship between education and volunteering, holding unobservable family effects constant. Results show that education significantly reduces the probability of volunteering and the supply of volunteer hours. Volunteering may not be an external benefit of education. (Contains 18…

In this paper we test the hypothesis advanced by Weiss ("J. Economic Perspectives" 9(4)(1995)133) that under sorting models the return to schooling across identical twins would decline over time compared to the return for the population as a whole. The analyses undertaken on a relatively large sample of Australian twins are consistent…

Reexamines Ashenfelter and Krueger's estimates of schooling returns (13%), using three additional years of the same twins survey. Finds a 10% return per year of schooling completed. The within-twin regression estimate of schooling's effect in the log wage is smaller than the cross-sectional estimate. (14 references) (MLH)

Summarizes the literature on twins-based estimations of schooling returns. Examines implications of endogenous determination of which twin goes to school longer and of measuring schooling with error. Twin-based estimation may complement other methodologies, but is vulnerable to the same inconsistency that afflicts conventional cross-sectional…

Data from a large sample of Australian twins indicate that 50 to 65 percent of variance in educational attainments can be attributed to genetic endowments. Only about 25 to 40 percent may be due to environmental factors, depending on adjustments for measurement error and assortative mating. (Contains 51 references.) (MLH)

Recent within-twin estimates of schooling returns are considerably higher than existing estimates. This paper shows that small ability differences among twins can yield more upward omitted-ability bias (and more upward bias overall) in the instrumental variables estimate correcting for measurement error than in the standard within-twin estimate.…