@unpublished{Attanasio2003,
author = {Orazio Attanasio and Costas Meghir and Miguel Székely},
title = {Using randomized experiments and structural models for 'scaling up': evidence from the PROGRESA evaluation},
year = {2003},
month = {May},
volume = {pp},
issn = {1742-0415},
url = {http://www.ifs.org.uk/edepo/wps/ewp0403.pdf},
}