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Open Access Publications from the University of California

Published articles of faculty and affiliated researchers at the Department of Economics, University of California at Santa Barbara.

Cover page of Father Absence and the Educational Gender Gap

Father Absence and the Educational Gender Gap


The educational attainment of young women now exceeds that of young men in most of the developed world, and women account for about 60% of new four-year college graduates in the United States. Several studies have suggested that the increase in single-parent households may be contributing to the growing gender gap in education, as boys are more vulnerable to the negative effects of father absence and economic disadvantage than girls. Using data on recent cohorts of young men and women from the National Longitudinal Study of Adolescent to Adult Health (Add Health), I find evidence consistent with other studies that boys are relatively more likely to experience problems in school, including school suspensions, when their father is absent, but also that girls are relatively more likely to experience depression in adolescence, particularly in step-father families. By the time Add Health subjects are young adults, there is no evidence that father absence early in life is more strongly associated with lower rates of college graduation for men, compared to women, in either cross-sectional or family fixed-effect models.

Cohabitation and the Uneven Retreat from Marriage in the U.S., 1950-2010


Since 1950 the sources of the gains from marriage have changed radically. As the educational attainment of women overtook and surpassed that of men and the ratio of men's to women's wage rates fell, traditional patterns of gender specialization in work weakened. The primary source of the gains to marriage shifted from the production of household services and commodities to investment in children. For some, these changes meant that marriage was no longer worth the costs of limited independence and potential mismatch. Cohabitation became an acceptable living arrangement for all groups, but cohabitation serves different functions among different groups. The poor and less educated are much more likely to rear children in cohabitating relationships. The college educated typically cohabit before marriage, but they marry before conceiving children and their marriages are relatively stable. We argue that different patterns of childrearing are the key to understanding class differences in marriage and parenthood, not an unintended by-product of it. Marriage is the commitment mechanism that supports high levels of investment in children and is hence more valuable for parents adopting a high-investment strategy for their children.

Educational Inequality and the Returns to Skills


Research and policy discussion about the diverging fortunes of children from advantaged and disadvantaged households have focused on the skill disparities between these children – how they might arise and how they might be remediated. Analysis of data from the National Longitudinal Study of Adolescent Health reveals another important mechanism in the determinants of educational attainment – differential returns to skills for children in different circumstances. Though the returns to cognitive ability are generally consistent across family background groups, personality traits have very different effects on educational attainment for young men and women with access to different levels of parental resources. These results are consistent with a model in which the provision of focused effort in school is complementary with parental inputs while openness, associated with imagination and exploration, is a substitute for information provision by educated parents and thus contributes to resilience in low-resource environments. In designing interventions to improve outcomes for disadvantaged children, we need to be cognizant of interactions between a child's skills and their circumstances.

Cover page of Cost-Effectiveness Analysis of Branded Drugs With Market Demand and Insurance.

Cost-Effectiveness Analysis of Branded Drugs With Market Demand and Insurance.



Cost-effectiveness analysis of branded pharmaceuticals presumes that both cost (or price) and marginal effectiveness levels are exogenous. This assumption underlies most judgments of the cost-effectiveness of specific drugs. In this study, we show the theoretical implications of letting both factors be endogenous by modeling pharmaceutical price setting with and without health insurance, along with patient response to the prices that depend on marginal effectiveness. We then explore the implications of these models for cost-effectiveness ratios.


We used simple textbook models of patient demand and pricing behavior of drug firms to predict market equilibria in the drug and insurance markets and to generate calculations of the cost-effectiveness ratios in those settings.


We found that ratios in market settings can be much different from those calculated in cost-effectiveness studies based on exogenous prices and treatment of all patients at risk rather than those who would demand treatment in a market setting. We also found that there may be considerable similarity in these market cost-effectiveness ratios across different products because drug firms with market power set profit-maximizing prices.


We found that market cost-effectiveness ratios will always indicate an excess of benefits over cost. Insurance will lead to less favorable ratios than without insurance, but when insurers bargain with drug firms, rather than taking their prices as given, cost-effectiveness ratios will be more favorable.

Cover page of Bacille Calmette-Guérin Vaccination in Infancy Does Not Protect Against Coronavirus Disease 2019 (COVID-19): Evidence From a Natural Experiment in Sweden.

Bacille Calmette-Guérin Vaccination in Infancy Does Not Protect Against Coronavirus Disease 2019 (COVID-19): Evidence From a Natural Experiment in Sweden.



The bacille Calmette-Guérin (BCG) tuberculosis vaccine has immunity benefits against respiratory infections. Accordingly, it has been hypothesized to have a protective effect against coronavirus disease 2019 (COVID-19). Recent research found that countries with universal BCG childhood vaccination policies tend to be less affected by the COVID-19 pandemic. However, such ecological studies are biased by numerous confounders. Instead, this paper reports on a rare nationwide natural experiment that occurred in Sweden in 1975, where discontinuation of newborns' BCG vaccination led to a dramatic decrease in BCG coverage rate, thus allowing us to estimate BCG's effect without the biases associated with cross-country comparisons.


Numbers of COVID-19 cases and hospitalizations were recorded for birth cohorts born just before and just after 1975, representing 1 026 304 and 1 018 544 individuals, respectively. We used regression discontinuity to assess the effect of BCG vaccination on COVID-19-related outcomes. On such a large population, this method allows for a precision that would be hard to achieve using a randomized controlled trial.


The odds ratios (95% CI) for COVID-19 cases and COVID-19-related hospitalizations were 1.0005 (.8130-1.1881) and 1.2046 (.7532-1.6560), allowing us to reject fairly modest effects of universal BCG vaccination. We can reject with 95% confidence that universal BCG vaccination reduces the number of cases by 19% and the number of hospitalizations by 25%.


While the effect of a recent vaccination must be evaluated, we provide strong evidence that receiving the BCG vaccine at birth does not have a protective effect against COVID-19 among middle-aged individuals.

Cover page of Global evidence for ultraviolet radiation decreasing COVID-19 growth rates.

Global evidence for ultraviolet radiation decreasing COVID-19 growth rates.


With nearly every country combating the 2019 novel coronavirus (COVID-19), there is a need to understand how local environmental conditions may modify transmission. To date, quantifying seasonality of the disease has been limited by scarce data and the difficulty of isolating climatological variables from other drivers of transmission in observational studies. We combine a spatially resolved dataset of confirmed COVID-19 cases, composed of 3,235 regions across 173 countries, with local environmental conditions and a statistical approach developed to quantify causal effects of environmental conditions in observational data settings. We find that ultraviolet (UV) radiation has a statistically significant effect on daily COVID-19 growth rates: a SD increase in UV lowers the daily growth rate of COVID-19 cases by ∼1 percentage point over the subsequent 2.5 wk, relative to an average in-sample growth rate of 13.2%. The time pattern of lagged effects peaks 9 to 11 d after UV exposure, consistent with the combined timescale of incubation, testing, and reporting. Cumulative effects of temperature and humidity are not statistically significant. Simulations illustrate how seasonal changes in UV have influenced regional patterns of COVID-19 growth rates from January to June, indicating that UV has a substantially smaller effect on the spread of the disease than social distancing policies. Furthermore, total COVID-19 seasonality has indeterminate sign for most regions during this period due to uncertain effects of other environmental variables. Our findings indicate UV exposure influences COVID-19 cases, but a comprehensive understanding of seasonality awaits further analysis.

Educational Gender Gaps.


Cross-country studies reveal two consistent gender gaps in education-underachievement in school by boys and low rates of participation in STEM studies by girls. Recent economics research has shown the importance of social influences on women's STEM avoidance, but male low achievement has been less-studied and tends to be attributed to behavior problems and deficient non-cognitive skills. I revisit the determinants of the gender gap in U.S. educational attainment with a relatively-advantaged sample of young men and women and find that school behavior and measured skills are not very important drivers of gender differences, particularly in the transition to college. Educational aspirations, on the other hand, are strongly predictive of educational gaps and the gender difference in aspirations cannot be explained, even with rich adolescent data that includes parental expectations and school achievement indicators. These results suggest that gender identity concerns may influence (and damage) the educational prospects of boys as well as girls through norms of masculinity that discourage academic achievement.