1150 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

areas is approximately #59, greater than for the industrial
areas. In the low income areas, despite the high income elasticities
 and modest increases in per capita income, most of the
increase in demand results from population growth. If Latin
America were to have a 39, annual increase in GNP per capita,
 the demand growth for food would be in excess of 49,
annually. This would require a doubling of food output in
about 18 vears.

C. Economic Development and the Supply of Agricultural
Products

In the discussion of the general frame-work of the relationship
 between agriculture and economic development the discussion
 of changes in supply were largely in terms of output changes
 that had to occur if economic development were to occur.
[t is time now to turn to a discussion of the major factors that
lead to output increases. The following classification includes
nothing that is new, but is useful for organizing our discussion.
 Increased agricultural output occurs as a result of one
or more of the following: 1) increased use of inputs; 2) improving
 the quality of inputs; 3) increased knowledge or a
change in the production function, and 4) a change in incentives
for farm operators and their families.
If all of the increased output must come as a result of
increased labor and land, it is unlikely that agriculture will
be able to make any significant contribution to economic development
 (1). If this is the case. the growth of the agricul-(')

 This observation may well have been correct for the United States
in the period before 1860. Given the large quantity of land that was available
 for settlement, it was possible to expand output of farm products
without changing the relative combination of land to labor. Admittedly
scanty evidence for the period from 1820 through 1860 indicates the follow-161

 Johnson - pag. 10