The Geographic Factors which Determine the Location of Com mercial discussing the location of commercial centers let us first consider their general distribution throughout the world, and second their distribution in respect to local conditions. The general distribution of the three types of commercial centers, primi tive, simple, and complex, is almost the same as that of the correspond ing types of manufacturing communities. It is illustrated by the map of civilization, Fig. 25. Only in the regions of " very high " civilization do we find the highly complex type of commercial center, for only there do race, health, and historical development produce not only extremely active trade, and the most complex kind of manufacturing, but great accumulations of capital, the power to control large enterprises in other parts of the world, and the qualities which make a financial as well as a commercial and manufacturing center. How much these conditions have to do with the growth of large cities may be judged from the fact that of the world's 90 largest cities 47, or more than half, are located in the small dark areas of Fig. 25 where conditions of the greatest progress and energy cause almost every great city to combine complex manufacturing, commerce, and finance. Of the remaining cities 18 are located in regions of high civilization, the second grade in Fig. 25, and have a large amount of simple manufacturing and some financial importance, and 20 are located in the enormously populous areas of " medium " civilization where the inhabitants are progressive enough to have at least a moderate amount of simple manufacturing. This leaves only 5 great cities in the vast regions of low civilization, and none in those that are very low.
The Character of the Hinterland.—Having grouped the commercial centers according to their relation to civilization in general and manu facturing in particular, we find that the next factor in determining their character and size is the nature of their hinterlands. The hinter land proper is the immediate country upon which the city depends for existence, and is distinct from the more distant regions with which the city is in intimate connection. It is the region whose surplus products the city disposes of and whose demands it tries to supply; the more distant regions arc those to which the city reaches out in order to find a market for its hinterland's surplus and to obtain the products which its hinterland does not produce. The commercial city is like a giant sitting at the gateway of his estate. With one hand he sweeps up the products which the people of his hinterland prepare; with the other he reaches far out to other people, strangers perhaps, and offers his people's products in exchange for something which he can hand back to his own subjects. Kansas City, for example, receives corn, wheat, cattle, and other agricultural produce from its hinterland, which lies mainly to the west of it. It sells its goods largely in the manufacturing
cities of the East and even in Europe where Kansas beef, pork, and flour feed the workers who make machinery, cloth, railway cars, and articles of adornment. The hinterlands of cities may overlap, for example that of St. Louis overlaps and partially includes that of Kansas City, for many of the goods that are shipped to or from the latter are bought or sold by merchants in St. Louis. In the same way the hinterland of Chicago overlaps that of both St. Louis and Kansas City, while that of New York extends over most of the northern United States as far as the Rocky Mountains.
The products received from the hinterland of a coastal commercial center are rarely of the same bulk and value as those sent out to other regions. This is evident in many of the cities in Table 40. Regions with more exports than imports have what is called a favorable balance of trade (see Table 39 K), while those with more imports than exports have an unfavorable balance (Table 39 L). An excess of imports over exports, however, is by no means necessarily an unfavorable sign, espe cially if a city engages in entrepa trade or is a great financial center. At London, for example, in 1913, for every hundred dollars' worth of exports there were $161 of imports. This is because London is a great financial and shipping center. Therefore large sums must be paid to it by foreign countries for interest on investments and for carrying freight in the ships which it owns. These sums are paid in goods, not currency, and hence the imports must exceed the exports. In other cases such as Calcutta, Alexandria, and especially Galveston the imports are small compared with the exports. In such cases a few raw materials, jute and cotton in the present instances, are raised in great quantities in the hinterlands of the ports and are shipped in an almost unmanufactured state. In general an undeveloped region with only primitive or simple manufactures exports more than it imports, while the highly developed country imports a great deal and balances this against its investments. The character of a city depends very largely on the nature of the hinterland as thus indicated, for where the product is chiefly raw materials and food the activity is slight. The manufacturing and financial centers that want these products are the places where most of the active buying and selling is done. Thus although both New Orleans and Galveston carry on a greater foreign commerce than Boston or Philadelphia, their role is relatively passive. Their commercial activity is much less than that of the northern cities where exports and imports are more nearly equal and more varied so that they require much more planning in order to prepare and sell them.