Alston, Julian M.; Marra, Michele C.; Pardey, Philip G.; … - International Food Policy Research Institute (IFPRI) - 1998
A total of 294 studies of returns to agricultural R&D (including extension) were compiled and these studies provide 1,858 separate estimates of rates of return. This includes some extreme values, which are implausible. When the highest and lowest 2.5 percent of the rates of return were set...