BACKGROUND : During the last 30 years, the physical, cultural, and socioeconomic environment in which cropping is carried out has changed in much of Africa. Population densities and population growth rates have increased; arable land per capita, soil quality, and tree cover have declined; input and credit markets have changed; and (2) argue that better coordination of macro and the relative importance of non-farm income has risen. African governments and donors have devoted much time, effort, and money to identify constraints, to develop new technologies, and to change the policy environment so that farmers can better cope with their evolving environment, thus raising farm output and productivity. As governments implement new agricultural policies and programs, it is imperative that they accurately monitor their effect on productivity. Poor agricultural data and inappropriate analyses can lead to misallocation of scarce resources and policy formulation that fails to resolve critical development and productivity problems.