The first reason is geography, Dr.Gallup and Saches find that location and geography have large effects on income level and income growth. When they identified geographical regions which are not conducive to modern economic growth, they find that the countries in the geographical tropics are nearly all poor, and costal economics are generally higher income than the landlocked economics. For instance, the GDP of coastal areas is almost three times more than Sri Lanka which is located in the tropical area. Residents who live nearly the coastal areas, theie financial can be improved by sea trade, such as, far sea fishers, offshore fisheries and so on.
On the other hand, nations in tropical climate zones generally face higher rate of infections disease and lower chance for fisher productivity than do nations in the coastal zones.
Another reason can be seen by them is that geography also affects the agricultural productivity in a country. For the major food grains – wheet, maize and crops, wheet grows mainly in temperate climate, maize and crops generally more productive in temperate and subtropical climates than in tropical zones. On average, a hectare of land in the tropical yields are almost three time less than the hectare in the temperate zone yields. Farming in tropical rain forest environments is harmpered by the fragility of the soil, there are wet and dry seasons in tropical environments, farmers must against the rapid lost of the