Open research assistant position for Fall quarter

I am looking for a research assistant (RA) for a project that examines how the determinants of urban fertility vary across countries and to help organize a conference around the same topic. The RA will assist with data management, literature searches, and running estimations. The ideal candidate is interested in quantitative analyses, has a working knowledge of RStudio, and can commit to 5-10 hours a week for the Fall quarter. The pay is $16 an hour, and the hours are flexible. To apply, please email me a short statement of interest, a resume, an unofficial transcript, and an example of your R code, if you have one, by close of business Monday 21 October 2019.

Please contact me if you have any questions about the project or the position.

PS To apply for this position, you have to be a student at Seattle University (graduate or undergraduate).

How competitive are online labor markets?

One would expect that online labor markets are competitive. After all, there are many employers and many employees, and most of the labor markets have a high degree of flexibility. Recent papers suggest, however, that employers have substantial market power, even in markets such as Mechanical Turk. This is based on a low labor supply elasticity facing employers (if an employer changes the offered wage, the response in terms of how many people will want to work is relatively small). In a new paper, "What Labor Supply Elasticities do Employers Face? Evidence from Field Experiments," Nail Hassairi and I, show, using experimental data from Mechanical Turk, that this result is likely due to the way prior experiments and research was done. The paper is available here and the abstract is below.

We provide experimental evidence on the labor supply elasticity faced by employers, which is an essential measure of employer market power. We offered two different types of jobs, each with large randomized variations in pay, and observed the amount of work performed. We find no evidence of the strong employer market power suggested by prior research, with our elasticities close to unity. Furthermore, elasticities based on the total amount of work are significantly larger than if we use worker-level data as prior studies have done. Finally, elasticities differ by job type, suggesting that worker characteristics play a crucial role.

Birth Spacing in the Presence of Son Preference and Sex-Selective Abortions: India’s Experience over Four Decades

My latest paper, on how birth spacing changed in India with the introduction of sex selection, is now available. I am presenting a poster on this paper this coming Friday at the Population Association of America's annual meeting in Denver.


Birth Spacing in the Presence of Son Preference and Sex-Selective Abortions: India’s Experience over Four Decades


Strong son preference is typically associated with shorter birth spacing in the absence of sons, but access to sex selection has the potential to reverse this pattern because each abortion extends spacing by six to twelve months. I introduce a statistical method that simultaneously accounts for how sex selection increases the spacing between births and the likelihood of a son. Using four rounds of India’s National Family and Health Surveys, I show that, except for first births, the spacing between births increased substantially over the last four decades, with the most substantial increases among women most likely to use sex selection. Specifically, well-educated women with no boys now exhibit significantly longer spacing and more male-biased sex ratios than similar women with boys. Women with no education still follow the standard pattern of short spacing when they have girls and little evidence of sex selection, with medium-educated women showing mixed results. Finally, sex ratios are more likely to decline within spells at lower parities, where there is less pressure to ensure a son, and more likely to increase or remain consistently high for higher-order spells, where the pressure to provide a son is high.

Online versions of forthcoming papers

My paper with Shamma Alam on shocks and timing of fertility in Tanzania, which forthcoming in Journal of Development Economics, is now available here. A free version if available until early February through this link.

My paper with Yu-hsuan Su on child health across urban, slums, and rural area, which is forthcoming in Demography, is available here.

Open research assistant position for Fall quarter

I am looking for a research assistant (RA) to work on a project that examine how determinants of urban fertility vary across countries. The RA will be help clean and merge data from many different countries, research education systems in these countries, code variables, and, if time permits, run analyses. The minimum requirements are a working knowledge of RStudio (for example, currently taking or having taken an upper-level undergraduate course like Econ 4770 or similar), great attention to detail, and the ability to commit to 5-10 hours a week of work for the Fall quarter. A knowledge of other programming languages, GitHub, and basic Unix commands would be a plus since all work will be done on a University of Washington server.

The pay will be $15 an hour and hours are flexible. To apply please email me a short statement of interest, a resume, an unoffical transcript, and an example of your R code by close of business 6 October. Shortlisted candidates may receive a short "test" assignment based on the project.

Please contact me if you have any questions about the project or the position.

PS To apply for this position, you have to be a student at Seattle University (graduate or undergraduate).

Paper on child health in India forthcoming in Demography

My paper with Yu-hsuan Su, "Differences in Child Health across Rural, Urban, and Slum Areas: Evidence from India," has been accepted for publication in Demography. The final version is here and the abstract for the paper is below.

The developing world is rapidly urbanizing, but our understanding of how child health differs across urban and rural areas is lacking. We examine the association between area of residence and child health in India, focusing on composition and selection effects. Simple height-for-age averages show that rural Indian children have the poorest health and urban children the best, with slum children in between. Controlling for wealth or observed health environment, the urban height-for-age advantage disappears, and slum children fare significantly worse than their rural counterparts. Hence, differences in composition across areas mask a substantial negative association between living in slums and height-for-age. This association is more negative for girls than boys. Furthermore, a large number of girls are "missing" in slums. We argue that this implies that the negative association between living in slums and health is even stronger than our estimate. The "missing" girls also help explain why slum girls appear to have a substantially lower mortality than rural girls do, whereas slum boys have a higher mortality risk than rural boys do. We estimate that slum conditions–which the survey does not adequately capture, such as overcrowding and open sewers–are associated with 20-37% of slum children's stunting risk.

New version of paper on sex-selective abortions in India

A new version of my paper on sex-selective abortion, fertility, and birth spacing in India is now available. The major change from the prior version is new theoretical model that better ties the theoretical and empirical parts of the paper together plus many edits throughout the paper. The new version is available here and the new online appendix here.

Control of fertility using only traditional contraceptives?

Shamma Alam and I just finished a paper on the effects of income shocks on the timing of fertility in Tanzania using the Kagera data set. There are significant reductions in the likelihoods of being pregnant and giving birth following shocks, consistent with prior results in the literature. What is new is that we can show that this is predominately the results of an increased use of contraceptives. This is interesting for two reasons. First, it shows that the postponement of fertility following a shock is the result of an conscious decision, rather than being an unintended consequence of the shocks' effect on, for example, health or migration. Second, the postponement is achieved almost entirely through the use of traditional contraceptives. This shows that, once the incentives are strong enough, people are able to control their fertility even in the absence of modern contraceptives. The full abstract is:

This paper examines the relationship between household income shocks and fertility decisions. Using panel data from Tanzania, we estimate the impact of agricultural shocks on pregnancy, births, and contraception use. We estimate individual level fixed effect models to account for potential correlation between unobservable household characteristics and both shocks and decisions on fertility and contraceptive use. The likelihood of pregnancies and childbirth are significantly lower for households that experience a crop shock. Furthermore, women significantly increase their contraception use in response to crop losses. We find little evidence that the response to crop loss depends on education or wealth levels. The increase in contraceptive use comes almost entirely from traditional contraceptive methods, such as abstinence, withdrawal, and the rhythm method. We argue that these changes in behavior are the result of deliberate decisions of the households rather than the shocks' effects on other factors that influence fertility, such as women’s health status, the absence or migration of a spouse, the dissolution of partnerships, or the number of hours worked. We also show that, although traditional contraceptives have low overall efficacy, households with a strong incentive to postpone fertility are very effective at using them.

New version of my paper on sex-selective abortions in India

After working through many and excellent comments from 3 referees, I now have a revised version of my paper on sex-selective abortions in India. There is also now a substantial on-line appendix (89 pages). The new abstract is:

This paper addresses two main questions: what is the relationship between fertility and sex selection and how does birth spacing interact with the use of sex-selective abortions? I introduce a statistical method that incorporates how sex-selective abortions affect both the likelihood of a son and spacing between births. Using India's National Family and Health Surveys, I show that falling fertility intensifies use of sex selection, leading to use at lower parities, and longer spacing after a daughter is born. Women with 8 or more years of education, both in urban and rural areas, are the main users of sex-selective abortions and have the lowest fertility. Women with less education have substantially higher fertility and do not appear to use sex selection. Predicted lifetime fertility for high-education women declined more than 10% between 1985–1994, when sex selection was legal, and 1995–2006, when sex selection was illegal. Fertility is now around replacement level. Abortions per woman increased almost 20% for urban women and 50% for rural women between the two periods, suggesting that making sex selection illegal has not reversed its use. Finally, sex selection appears to be used to ensure one son rather than multiple sons.

Parental absence paper published in Review of Economics of the Household

My paper, "Effects of Parental Absence on Child Labor and School Attendance in the Philippines," was published in the Review of Economics of the Household, vol. 14(1), pp 103-130, 2016.

This paper uses longitudinal data from the Philippines to analyze determinants of children’s time allocation. The estimation method takes into account both the simultaneity of time use decisions, by allowing for correlation of residuals across time uses, and unobservable family heterogeneity, through the inclusion of household fixed effects. Importantly, this improved estimation method leads to different results than when applying the methods previously used in the literature. Girls suffer significantly from the absence of their mother with a reduction in time spent in school that is equivalent to dropping out completely. This effect is substantially larger when controlling for household unobservables than when not. Boys increase time spent working on market related activities in response to an absent father, although this time appears to come out of leisure rather than school or doing household chores. Land ownership substantially increase the time boys spend on school activities, whereas renting land reduces the time girls spend on school. Finally, there does not appear to be a substantial trade-off between time spent on school and work, either in the market or at home.

Compensating wage differentials in an online labor market

We have recently finished the first in a series of planned papers based on experiments that we ran. The first paper is on the compensating wage differentials theory, with the title "Only if You Pay Me More: Field Experiments Support Compensating Wage Differentials Theory". Abstract below:

Compensating wage differentials is Adam Smith’s idea that wage differences equalize differences in job and worker characteristics. Other than risk of death, however, no job characteristics have consistently been found to affect wages, likely because of problems with self-selection and unobservable job characteristics. We run experiments in an online labor market, randomizing offered pay and job characteristics, thereby overcoming both problems. We find, as predicted by our model, that increasing job disamenities significantly reduces both likelihood of working and amount of work supplied. Correspondingly, the wage increases necessary to compensate workers for worse job disamenities are substantial, supporting the theory.

"High School Dropouts and Sexually Transmitted Infections" accepted at Southern Economic Journal

Mark Anderson and my paper, "High School Dropouts and Sexually Transmitted Infections," has been accepted for publication at the Southern Economic Journal. Not sure about the exact publication date yet. The abstract for the paper is:

People who drop out of high school fare worse in many aspects of life. We analyze the relationship between dropping out of high school and the probability of contracting a sexually transmitted infection (STI). Previous studies on the relationship between dropout status and sexual outcomes have not empirically addressed unobserved heterogeneity at the individual level. Using fixed effects estimators, we find evidence supporting a positive relationship between dropping out of high school and the risk of contracting an STI for females. Furthermore, we present evidence that illustrates differences between the romantic partners of dropouts versus enrolled students. These differences suggest that female dropouts may be more susceptible to contracting STIs because they partner with significantly different types of people than non-dropouts. Our results point to a previously undocumented benefit of encouraging those at risk of dropping out to stay in school longer.

XXVII IUSSP International Population Conference

Just back from the XXVII IUSSP International Population Conference, held in Busan, Korea. I presented my paper on family planning in Ethiopia (joint with Kathleen Beegle and Luc Christaensen) and a poster on my work on sex selective abortions in India. My student, Shamma Alam, presented our joint paper on income shocks and timing of fertility in Tanzania.

All-in-all it was a great conference and very well-organized. Only complaint was that many of the best US demographers did not attend. Quality of the sessions were a little more varied than what you find at the PAA, but I will be back again in four years. Finally, if you get a chance to go to Korea: take it; it is a wonderful place to visit.

New paper on the link between parental and offspring longevity in the US

My latest paper is on the relationship between how long your parents' live/lived and your expected survival. Turns out that even with improve medical care, health knowledge, etc, you still cannot be too careful in choosing your parents. The longer your parents live, the lower is your mortality risk. The paper is joint with my former graduate student Edwin Wong. You can find the paper here and the abstract is below.

Studies of adult mortality typically examine the impact of individual characteristics, but ignore the fact that the characteristics of people closely linked to those individuals also influence mortality risk. This paper examines the effect of parental longevity on survival outcomes of adult offspring using survey data from the University of Michigan Health and Retirement Study (HRS) between 1992 and 2008. It employs a competing risk model that controls for correlation between individual death and survey non-response. There is strong evidence that individuals with longer-lived parents exhibit lower mortality risk. Even after controlling for health conditions and behavioral variables of the offspring, parental age at death has a substantial impact on the survival of the adult offspring, suggesting a strong genetic component that must be considered as important in determining longevity.

New version of paper on family planning in Ethiopia available.

A new version of my paper with Kathleen Beegle and Luc Christiaensen on the effectiveness of family planning programs in Ethiopia is now available. You can find it here. The abstract is below.

Although reproductive health advocates consider family planning programs the intervention of choice to reduce fertility, there remains a great deal of scepticism among economists as to their effectiveness, despite little rigorous evidence to support either position. This study explores the effects of family planning in Ethiopia using a novel set of instruments to control for potential non-random program placement. The instruments are based on ordinal rankings of area characteristics, motivated by competition between areas for resources. Access to family planning is found to reduce completed fertility by more than 1 child among women without education. No effect is found among women with some formal schooling, suggesting that family planning and formal education act as substitutes, at least in this low income, low growth setting. This provides support to the notion that increasing access to family planning can provide an important, complementary entry point to kick-start the process of fertility reduction.