A recent study by de Carvalho Filho (2008) on Brazil uses a triple differences-in-differences approach and exploits a major reform of Preuidencia Rural that took place in 1992 and introduced a simultaneous change in age eligibility, an increase in the amount of the benefit and expanded eligibility to non-heads of households. The study presents evidence of reduced employment rates and total hours of work associated with the generous transfer to rural labourers. Given that the programme is not means-tested but instead universal for workers in rural areas, the negative impact of Preuidencia Rural on labour supply reflects a pure income effect associated with a fairly generous transfer amounting to 36% of average wages.