One of the hardest things about doing research on poverty can be finding people for follow-up visits, especially in urban areas like Accra, Ghana, where I work. As a rule Accra has no helpful signs, street names, or addresses. Directions are based on landmarks, whose defining feature is usually that it's something old -- the types of things that are obvious if you've lived there forever, but make no sense when you're new to the city. The resulting irony is that the most expensive thing about our research can be the time spent finding people to research.

Why millions of the world´s poor still choose to go private (from The Financial Times)

Even though public school teachers and public doctors tend to be much more qualified (and cheaper to access) than their private sector counterparts, people in the developing world tend to choose the private option.

Interesting example of the endowment effect from New York Times restaurant critic Frank Bruni: http://www.nytimes.com/2009/08/19/dining/19note.html?8dpc

Summing up the quirky behaviors of his dining companions over his tenure as restaurant critic for the NY Times, Bruni describes the way his fellow diners--to whom he had randomly assigned dishes to be sampled--would become protective of "their" choices, defending their quality.

IPA field staff are used to using lotteries to determine treatment and control groups for randomized control trials.  Some of our Research Affiliates have also used existing government lotteries (visas for migration to New Zealand and school vouchers in Colombia, for example) as natural field experiments.