Sirs:

	Ansley Coale [The History of the Human Population, \F1Scientific
American\F0, September] misses some population control mechanisms
that may have been important in previous static societies and may
become important in the future.  Both folk tales and 18th and 19th
century literature give the impression that a person could not marry
and reproduce unless he inherited one of a fixed set of social slots.
In such a society, the response to an upward fluctuation in births
would not necessarily be an increased death rate; it might simply be
a reduction in marriage rate.  Traditional society had many places for
people which didn't allow these people to marry:
dependents in families, domestic servants of
lower rank, many soldiers and sailors, and the church.
The mechanism could serve to control not merely the population as a whole
but also the numbers of people in particular occupations and stations
in society.  In the case of land, most countries had laws that prevented
subdivision of estates, and many occupations had rules designed to prevent
the number of workers from increasing.

	Industrialization makes this method of population control
ineffective by the creation of a sizable labor market.
Once the ability
to get a job in certain industries is no longer inherited, and once
these occupations provide the cash to rent housing of however poor
quality, the population will start increasing.  This might explain why
population increase started before medicine had advanced appreciably.

	If compulsory population control becomes necessary, it might take
the form of allocating job slots in society and making them inheritable.