Reflections on Impact Assessment

There are many useful spinoffs from exploring just what a program of agricultural research has achieved. These range from providing investors and other decision makers with pertinent information on the economic value of research, to providing a more complete understanding of what has been achieved, and then sharing this information with all parties to a research system. There are, however, many methodological difficulties inherent in such work and these vary from the challenge of measuring gains to knowledge, through the empirical difficulty of determining productivity effects (especially in relation to "counterfactual" situations), to dealing with attaching a value to the contributions of people involved in research activities. All these methodological issues should be broached. Attention is then turned to the practice of such a study, along with further difficulties that may be encountered and which must be dealt with. These include the difficulties of attribution among differ­ent, and sometimes competitive, agents working within what may be several distinct research systems, the possibilities for bias in all aspects of measurement, and the virtue of attempting to avoid (and being seen to be attempting to avoid) such biases. Particular reference is made to the impact study of the Consul­tative Group on International Agricultural Research (CGIAR) centers. The paper closes with a discussion of the possible impact of an impact study and the wider issues of agricultural policy that surround any analysis of investments in agricultural re­search.