756 Economic Development and Cultural Change declining population growth rates. Supply growth is meanwhile tained with the ongoing recovery of investment in agricultural research and irrigation. Chinas dynamic economy and rapidly changing structure may cause changes in the historic patterns of food trade. By 2010, for example, China could import rice and by 2020 become self-sufficient in wheat and one of the worlds largest importers of maize. here is considerable range in the projections, however, when base- line assumptions are varied in both the short and long run. Different rates of agricultural investment create some of the largest differences in Chi nas expected imports, but this is what should be expected from the fac tor that has the largest marginal output response. While there are a few enarios where projected levels of imports are somewhat large, from oth the viewpoint of Chinas own domestic needs and relative to the size of current world market trade, there are factors that may keep China from becoming too large of a player in world markets. First, world grain prices would certainly rise in the face of large Chinese imports, a ten dency that would dampen Chinese grain demand and stimulate domestic supply. Second, there may be major foreign exchange constraints to im- porting such large volumes of grain-either government policy makers will not allocate foreign exchange for additional grain imports or ex- change rate movements will discourage imports. Third, limitations on the ability of China,s ports and other parts of the nation's transportation and marketing infrastructure to handle large quantities of grains may co strain import levels Finally, and perhaps most important, many political economy in fluences may force China's leaders to react to increasing grain shortages Regardless of China's comparative advantage, government leaders have been historically, and continue to be, concerned with maintaining near self-sufficient domestic agricultural production capacity. National de- fense, pride, and ideology will necessarily put a premium on maintaining a rough balance between domestic demand and supply. On the basis of the results presented here, it appears that China will neither empty the world grain markets nor become a major grain ex porter. It does seem likely, however, that China will become a more im- portant player in world grain markets as an importer in the coming de- cades. Both potential exporters outside of China and those charged with anaging China's food needs through domestic production and imports eed to be ready. Exporting nations-especially those dealing with wheat(in the short run) and maize(in the long run)-will undoubtedly be the beneficiaries of these trends. If China's policy makers believe the projected levels of imports are too high(either politically or because they see some other physical or economic constraint), they will need to devise an investment strategy soon because of the long lags between the period of expenditure and the time when such investments can affect produc tion. Investment in facilities and institutions needed to handle the in Copyright 1999 All rights reserved.Copyright © 1999. All rights reserved