The association between cesarean birth and breastfeeding initiation in Odisha, India: A mother fixed effects analysis.

Cesarean births are becoming more common in India, with health implications for both mothers and infants. Between 2005 and 2015, the proportion of cesarean births to total births in India roughly doubled, from 9% to 17%. We analyze Annual Health Survey data from the state of Odisha in eastern India. These population-level, longitudinal data on births between 2007 and 2011 allows us to estimate the association between cesarean birth and breastfeeding outcomes using mother fixed effects. Mother fixed effects allow comparisons of siblings born to the same mother who experienced different types of births (vaginal and cesarean). This empirical strategy controls for many potential observable and unobservable confounders in the relationship. Ordinary Least Squares linear probability models without mother fixed effects find that babies born by cesarean in Odisha are about 14 percentage points (p<0.001) more likely to experience delayed initiation of breastfeeding (that is, not being breastfed in the first 24 hours) compared with babies born vaginally. After introducing mother fixed effects, we find that babies born by cesarean are 11 percentage points more likely to (p<0.001) experience delayed initiation of breastfeeding. Because breastfeeding success is important for protecting against infectious disease in this context, future research should investigate whether cesarean birth impacts other aspects of breastfeeding as well.

Research Note: Intergenerational Transmission Is Not Sufficient for Positive Long-Term Population Growth.

All leading long-term global population projections agree on continuing fertility decline, resulting in a rate of population size growth that will continue to decline toward zero and would eventually turn negative. However, scholarly and popular arguments have suggested that because fertility transmits intergenerationally (i.e., higher fertility parents tend to have higher fertility children) and is heterogeneous within a population, long-term population growth must eventually be positive, as high-fertility groups come to dominate the population. In this research note, we show that intergenerational transmission of fertility is not sufficient for positive long-term population growth, for empirical and theoretical reasons. First, because transmission is imperfect, the combination of transmission rates and fertility rates may be quantitatively insufficient for long-term population growth: higher fertility parents may nevertheless produce too few children who retain higher fertility preferences. Second, today even higher fertility subpopulations show declining fertility rates, which may eventually fall below replacement (and in some populations already are). Therefore, although different models of fertility transmission across generations reach different conclusions, depopulation is likely under any model if, in the future, even higher fertility subpopulations prefer and achieve below-replacement fertility. These results highlight the plausibility of long-term global depopulation and the importance of understanding the possible consequences of depopulation.

Mere Addition is equivalent to avoiding the Sadistic Conclusion in all plausible variable-population social orderings.

Economic policy evaluations require social welfare functions for variable-size populations. Two important axioms in the population ethics literature are Mere Addition and avoidance of the Sadistic Conclusion, both of which focus on the sign of lifetime utility. The population ethics literature treats these axioms as closely related but distinct: one influential review calls avoidance of the Sadistic Conclusion "less controversial." Here, we provide weak, uncontroversial sufficient conditions for these two principles to be equivalent. Related results exist in prior literature, but these include only same-number utilitarian orderings and therefore exclude recent and theoretically important rank-dependent social evaluations that we include. [100 words].