This is Mario Pareja, from Uruguay, again. This is in reply, or better in support of, Dr Suryadarma (Message 70). I stress the importance of the statement made in that message that "The central issue of impact evaluation is the validity of the counterfactual. Without an explicit construction of a counterfactual, there is no impact evaluation.". Absolutely! In our economic impact evaluation we concluded that the agricultural GDP without the National Institute of Agricultural Research (INIA) would have been 11% lower than the one achieved in 20 years by Uruguay. I translate, from Spanish, a statement on the economic conclusions that our economist, J. Bervejillo, wrote: "...taken as a starting point the year that INIA began its work, when the total factor productivity (TFP) reached a value of 124, we can state that without technological change between 1990 and 2009, the agricultural GDP would had been 2,795 million USD (that means, 68%, or 124/181). The residue of 32% corresponds to the increase in total productivity during the last 20 years. In 2009, this residue equalled 1,315 million USD. INIA is responsible for a fraction of the 32%". In relation to the other, so-called controversial, statement in Message 70, i.e. "Without quantitative estimates, there is no impact evaluation": It sounds great on paper, but it is almost impossible to apply that rigorously in the field. With the exception of the economic dimension, in which you may have quantitative data, the social and environmental impact evaluations - at least in our developing nations in which data collection systems are not fully functional and complete - often require qualitative information gathered from the direct users of the technologies as well as from the field technicians. I will detail the ones we use in future messages. Mario R. Pareja Ingeniero Agrónomo, M.S., Ph.D. independent consultant Paraje El Colorado, Canelones, Uruguay Telephone: 598-2-3654394 or 598-98372634 e-mail: parejamr (at) gmail.com [To contribute to this conference, send your message to [log in to unmask] For further information, see http://www.fao.org/nr/research-extension-systems/res-home/news/detail/en/c/217706/ ]. ######################################################################## To unsubscribe from the Impact-L list, click the following link: https://listserv.fao.org/cgi-bin/wa?SUBED1=Impact-L&A=1