"In general, farmers who are limited to traditional agricultural
factors are more secure in what they know about the factors they use
than farmers who are adopting and learning how to use new factors of
production. The new types of risk and uncertainty about the yield
inherent in factors embodying an advance in knowledge are of real
concern to farmers. They could be of critical importance to farmers
who are producing so little that there is barely enough production
for survival. But since traditional agriculture is not introducing
new factors, new elements of risk and uncertainty do not appear; they
arise only when the transformation gets under way." [Schultz, 1964, p.31]