Twin births are often construed as a natural experiment in the social and natural sciences on the premise that the occurrence of twins is quasi-random. We present new population-level evidence that challenges this premise. Using individual data for more than 18 million births (more than 500,000...

Twin births are often construed as a natural experiment in the social and natural sciences on the premise that their occurrence is quasi-random. We present new population-level evidence challenging this premise. Using data on about 18 million births in 72 countries, we find that maternal...

The lottery of birth draws some children into deprived environments and others into environments where they thrive. In a field experiment in rural India with 10-20 months old children we test two scalable interventions to reduce early disadvantages in health and mental development. We distribute...

The lottery of birth draws some children into deprived environments and others into environments where they thrive. In a field experiment in rural India with 10-20 months old children we test two scalable interventions to reduce early disadvantages in health and mental development. We distribute...

The lottery of birth draws some children into deprived environments and others into environments where they thrive. In a field experiment in rural India with 10-20 months old children we test two scalable interventions to reduce early disadvantages in health and mental development. We distribute...

Twin births are often used to instrument fertility to address (negative) selection of women into fertility. However recent work shows positive selection of women into twin birth. Thus, while OLS estimates will tend to be downward biased, twin-IV estimates will tend to be upward biased. This is...

This paper provides empirical evidence on the causal effects that upgrading slum dwellings has on the living conditions of the extremely poor. In particular, we study the impact of providing better houses in situ to slum dwellers in El Salvador, Mexico and Uruguay. We experimentally evaluate the...

We investigate the nature and origin of comorbidity, defined as the tendency of members of marital couples to display correlated patterns of ill-health in later life. In the absence of long-term prospective data on couples, we use long-range recall data from the pan-European SHARELife survey and...