Simulation of European
Migration:
Introduction
European
Simulation Program
This simulation of
the demography of European domestic and overseas migration enables the
user to project the effects of various conditions on the size and composition
of the populations involved. The procedure relies on standard demographic
techniques, approximating a continuous analysis of population change by
dividing populations into five-year age groups and assuming that all events
take place at the midpoint of five-year periods (see citations below for
detail).
As initial conditions,
the simulation assumes discrete groups known as Rural and Urban populations.
Members of the Rural population migrate: a given percentage of each age
and sex group migrates each year. (The term "migrants" refers to persons
in the high-mortality period of the first year following their migration,
after which they become "Resettlers" (in Europe) or "Settlers" (abroad).)
Migrants undergo an initial mortality, and are then divided into those
who remain in the cities of their home country, and those who emigrate
to the Americas. The latter group undergoes an additional mortality (corresponding
to the voyage across the Atlantic). The simulation keeps track of Rural
and Urban populations, Resettler (Europe) and Settler (Americas) populations,
and the number of migrants each year.
The user may select
varying input data files and one run parameter, as follows:
- Rural and Urban
populations: fertility and mortality rates, and intrinsic net growth
rates
- Migrant population:
size, age and sex composition, and mortality rates
- Resettler and
Settler populations: fertility and mortality rates, and intrinsic net
growth rates
- Length of simulation
(default is 40 years)
For the World Wide Web
version of the simulation, users may select any of five present groups of
input files, to see simulation results under five present groups of conditions.
(At present, only one set of input files is available.)
When run locally,
the simulation allows the user to create and utilize a limitless range
of input files.
Output of the program
includes population pyramids and calculations of relevant demographic
rates for the two initial populations, and for all the original, migrant
and settler populations in the last period of the simulation.
For further detail
on methodology and results, see Patrick Manning, "Slave Trade: The Formal
Demography of a Global System," Social Science History, vol. 14 (1990),
255-79; Nathan Keyfitz, Introduction to the Mathematics of Population
(New York, 1977); and P. Manning, Slavery and African Life (Cambridge,
1990).
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