Agricultural productivity has stagnated in much of sub-Saharan Africa, while many other regions of the world have seen dramatic productivity improvements in recent decades. New agricultural technologies, such as high-yielding crop varieties, offer the promise of improving productivity and hence the welfare of farmers. But adoption of these technologies has often been low in countries where dissemination programs have been conducted. First adopters of new technologies play an important role in the spread of technology as they take on the burden of experimentation—testing whether and how a new variety works in local conditions. This is particularly important in much of sub-Saharan Africa where a multiplicity of micro climates within a small area means that experimentation is essential for farmers to learn which crop varieties are best for their particular land. There is also concern that early subsidization to increase adoption of new technologies will lead to expectation of continued subsidies, depressing demand at market prices.