Estimates of the internal rate of return to public investments   agricultural research (conf.) The aggregate changes in agricultural productivity described in previous chapters are the cumulative effect of the adoption of such innovations. Adoption is largely driven by the desire of producers to increase the profitability of their farm operations. Market forces and price signals serve as powerful instruments to spur rapid adoption of productivity-enhancing technologies and practices. Extension and education activities, provision of financial and risk management services, and access to commodity and input markets improve the flow of information and uptake of innovations by farmers.