Amar Hamoudi

Is life expectancy really falling for groups of low socio-economic status? Lagged selection bias and artefactual trends in mortality

Recent public health studies made headlines, reporting that for some subpopulations in the USA, mortality rates have been higher and life expectancies lower for recent compared with earlier time periods. These patterns have been described in both popular and academic discourse as a ‘rise’ in mortality or a ‘decline’ in life expectancy. We suggest that it is long past time to admit an alternative—and arguably more plausible—interpretation of these patterns. The fact that a measure was computed at two different time points does not, by itself, make the difference between them a trend. Imagine if researchers measured the average temperature for the whole of the USA a decade ago, and then for only Alaska this year, and found the former number to be lower than the latter. Would it be appropriate to say that average temperatures had ‘declined’ over the decade? We argue that it would not, and that it is likewise not appropriate to be describing many of the observed differences in subgroup life expectancy or mortality as ‘trends’. Nevertheless, scholars and journalists alike have quickly adopted this ‘trend’ conclusion and given short shrift to an alternative interpretation that we find far more plausible. Here, we make the case that this alternative explanation should be the subject of serious empirical investigation and discussion in scholarly and public discourse, rather than getting the treatment it gets now— which is a cursory dismissal relegated to the ‘limitations’ sections of academic papers. We take seriously the reality of health disparities in the USA and the research and policy attention that they demand; understanding and redressing these disparities requires that trends be accurately characterized.

The effect of water quality testing on household behavior: evidence from an experiment in rural India.

How does specific information about contamination in a households drinking water affect water handling behavior? We randomly split a sample of households in rural Andhra Pradesh, India. The treatment group observed a contamination test of the drinking water in their own household storage vessel; while they were waiting for their results, they were also provided with a list of actions that they could take to remedy contamination if they tested positive. The control group received no test or guidance. The drinking water of nearly 90% of tested households showed evidence of contamination by fecal bacteria. They reacted by purchasing more of their water from commercial sources but not by making more time-intensive adjustments. Providing salient evidence of risk increases demand for commercial clean water.

Do Daughters Really Cause Divorce? Stress, Pregnancy, and Family Composition

Provocative studies have reported that in the United States, marriages producing firstborn daughters are more likely to divorce than those producing firstborn sons. The findings have been interpreted as contemporary evidence of fathers’ son preference. Our study explores the potential role of another set of dynamics that may drive these patterns: namely, selection into live birth. Epidemiological evidence indicates that the characteristic female survival advantage may begin before birth. If stress accompanying unstable marriages has biological effects on fecundity, a female survival advantage could generate an association between stability and the sex composition of offspring. Combining regression and simulation techniques to analyze real-world data, we ask, How much of the observed association between sex of the firstborn child and risk of divorce could plausibly be accounted for by the joint effects of female survival advantage and reduced fecundity associated with unstable marriage? Using data from the National Longitudinal Survey of Youth (NLSY79), we find that relationship conflict predicts the sex of children born after conflict was measured; conflict also predicts subsequent divorce. Conservative specification of parameters linking pregnancy characteristics, selection into live birth, and divorce are sufficient to generate a selection-driven association between offspring sex and divorce, which is consequential in magnitude. Our findings illustrate the value of demographic accounting of processes which occur before birth—a period when many outcomes of central interest in the population sciences begin to take shape.

Physical Health Effects of the Housing Boom: Quasi-Experimental Evidence From the Health and Retirement Study

OBJECTIVES We examined the impact of the dramatic increases in housing prices in the United States in the 1990s and early 2000s on physical health outcomes among a representative sample of middle-aged and older Americans. METHODS Using a quasi-experimental design, we exploited geographic and time variation in housing prices using third-party valuation estimates of median single-family detached houses from 1988 to 2007 in each of 2400 zip codes combined with Health and Retirement Study data from 1992 to 2006 to test the impact of housing appreciation on physical health outcomes. RESULTS Respondents living in communities in which home values appreciated more rapidly had fewer functional limitations, performed better on interviewer-administered physical tasks, and had smaller waist circumference. CONCLUSIONS Our results indicate that increases in housing wealth were associated with better health outcomes for homeowners in late middle age and older. The recent sharp decline in housing values for this group may likewise be expected to have important implications for health and should be examined as data become available.

Heterogeneous Effects of Information on Household Behaviors to Improve Water Quality

Providing information about health risks only sometimes induces protective action. This raises questions about whether and how risk information is understood and acted upon, and how responses vary across contexts. We stratified a randomized experiment across two periurban areas in Cambodia, which differed in terms of socioeconomic status and infrastructure. In one area, showing households specific evidence of water contamination altered their beliefs about health risk and increased their demand for a treatment product; in the other area, it had no effect on these outcomes. These findings highlight the importance of identifying specific drivers of responses to health risk information.