FRONTIERS^293
withdrawn after the failed second siege of Vienna (1685). Half a cen
tury later, the Russians opened the great Ukrainian breadbasket by
driving back the nomadic peoples that had roamed and vaguely ruled
these wide spaces since the days of the Golden Horde (mid-thirteenth
century).
The biggest frontiers, however, waited overseas: the Americas above
all, but also lesser spaces in Australia and southern Africa. None of
these lands was empty when the Europeans arrived. Everywhere, in
digenous peoples tilled the soil, raised their livestock, or just hunted
and gathered. But again, densities of settlement varied, dictating the
opportunity and circumstances of invasion. In the Americas, a few
areas were thickly settied—the valley of Mexico, the Peruvian hill coun
try, some Caribbean islands. Ordinarily such densities would have pre
cluded conquest, as they did in Asia, but the technological and political
weaknesses of the native American population made them vulnerable.
Imported pathogens did the rest. Elsewhere in the Americas, as in the
northern latitudes that became the United States and Canada, low
densities gave way to superior armament and organization. For the In
dians, the white man was stealing their land; for the white man, the
land lay before them for the taking, a boundless, profitable frontier.
Economists see the factors of production as land, labor, and capital.
Land subsumes not only surface area but the resources that lie under
neath; and from the point of view of economic development, the
salient characteristics of a frontier region are space, soil, and wealth of
materials. These in turn set opportunities and constraints: such lands
can yield abundance of primary products per head of population, but
only if they can get the necessary labor. They want people, whom they
often draw by offering incentives to migration: free or cheap land in
particular, but also higher wages, higher status, and political rights.
(This was a crucial aspect of the improvement of status and tenure in
medieval Europe.) And if voluntary labor does not come, they will im
port people by force, paying slave traders or recruiters to do the dirty
work.
Once the factors of production assembled, frontier lands typically
yield crops and other primary products far in excess of the needs of the
population. These surpluses then become tradables. These economies
can make so much more money producing cash crops for export than
by devoting themselves to subsistence farming that it pays them to
trade food security for income. (Witness the sugar islands of the
Caribbean, which devoted every square inch to cane and imported
victuals from as far away as Europe.)