One of the challenges facing prevention science is to demonstrate that a good program will be effective wherever in the world it is implemented. So a robust intervention developed in the US, for example, should have the potential to help children and families in Mexico – and vice versa. But, as Robert Slavin at Johns Hopkins University and the UK Institute for Effective Education has been finding, transporting successful models from the developing world to comparatively wealthier countries like the UK and US is fraught with difficulty. He has been examining efforts in both countries to follow the example of Mexico by using financial incentives to get children successfully through school.Mexico’s PROGRESA program (recently rechristened Opportunidades) allowed families in impoverished rural communities to claim up to $65.20 for each month that their children regularly attended school. Experimental results showed that PROGRESA children attended more, dropped out less and progressed through each school year with more ease. At the last count in 2003, PROGRESA was serving four million households in Mexico and was drawing on funding from the World Bank and other organizations. In the guise of “conditional cash transfer programs”, Mexico’s approach has been adopted in other developing countries, including Colombia, Ecuador, Costa Rica, Jamaica, Pakistan, Kenya, and Indonesia. Experiments have suggested a range of positive effects on children’s outcomes. But in the UK and the US, says Slavin, the results are far less encouraging. Studies show small increases in attendance but no concrete effects on learning or achievement.In one UK scheme, for example, students who completed their final year of compulsory education in 1999 and 2000 and whose parents had an income below £13,000 were eligible to receive £30-£40 a week if they entered further full-time education. The Educational Maintenance Allowance, as it was called, did get more 16-year-olds into further education, but by age 19 the effects had disappeared without having any impact on achievement.Contextual differences explain the comparative failure, he says. “Poverty in inner-city Manchester or Baltimore has little in common with poverty in rural Mexico or Kenya, where incomes are so low that small incentives for attending school can represent a significant proportion of families’ incomes.”In addition, policy makers in the developing world legitimately focus on school attendance to get children into education and out of the child labor market. But in the western world where child labor is not a significant problem, achievement and participation in further or higher education are the focus. When those are the aims, Slavin says, other kinds of intervention generally resting on the professional development for teachers, cost less, reach more children and prove more effective.