In contributing to the appraisal and evalution of technological innovation, agricultural economists have a major but changing role to play. Whereas hitherto the concern has been chiefly to compare sharply different exogenous and indigenous technologies, the challenge now is to assess technological change of either or both these kinds
in ecologically sensitive and relatively unproductive areas
when the bulk of the people are poor and survival is the most common preoccupation
where innovations could impinge at many points in household life‐systems but are, singly, likely to have only small impact
where the institutional structure will be crucial to their acceptance and might itself have to change.