For his migration study, Ravenstein compared census data
gathered in 1871 and 1881, the most recent tabulations
available at the time. In order to determine patterns of
movement, comparison of simple population totals would be
insufficient. "[T]he rate at which the population of each
kingdom increases does not correspond with the rate of
increase among the natives of each," Ravenstein observed. "It
need hardly be pointed out that this difference is due
primarily to emigration from foreign parts, and in a less
degree to migration from one kingdom into the other."
Toward this end, Ravenstein used additional survey
information detailing the birthplaces of those tallied. He
would compare the aggregate birthplace data with the current
population information of each county to get a general picture
of where people had ended up in relation to their places of
birth. The populations of all counties would be categorized
according to whether individuals were "natives" of the county
they were enumerated in at the time of the survey ("native
county element"), of an adjoining county ("border element"),
from within the same kingdom, from a separate kingdom, or from
outside the United Kingdom altogether ("foreign element").
At the heart of Ravenstein's emerging migration model were
the concepts of absorption and dispersion. He
defined a county of absorption as having "a population more or
less in excess of the number of its natives enumerated
throughout the kingdom." In other words, it was a country that
on the whole took in more people than it gave up. A county of
dispersion, then, would be one of the counties that on the
whole gave up population over time, or in Ravenstein's words,
"the population [of the county] falls short of the number of
[its] natives enumerated throughout the kingdom."
Since each census gathered specific data on the birth
counties of each individual, Ravenstein was able to generate
basic population flows between dispersion and absorption
centers, leading to the revealing map illustrated on this
page. Through a careful reading of the numbers, he was able to
sketch a rough picture of migration trends within the United
Kingdom. The counties of absorption "are the chief seats of
commerce and industry," Ravenstein concluded, whereas counties
of dispersion were "nearly all . . . agricultural."
In addition to the basic trends, Ravenstein was also able
to use the birthplace information to determine that
significant "counter-currents" of migration existed.
Significantly, he concluded that many of those moving away
from some of the absorption areas "have merely removed to what
are actually suburbs, and can hardly be said to have left the
metropolis." He also discovered that most people who were
natives of other counties had generally come from bordering
counties, leading to the idea that migrants generally make
shorter, rather than longer, moves.
Perhaps the most surprising result of Ravenstein's research
was the conclusion that the "woman is a greater migrant than
man." While "males more frequently venture beyond [the kingdom
of their birth]," women "are more migratory than males within
[it]." This he attributed to women seeking work outside of
their homes for domestic service as well as jobs in the shops
and factories of industrial centers.
Although Ravenstein's paper only focused on information
gleaned from surveys within the United Kingdom, he made the
bold jump of formulating from his observations a series of
seven "laws of migration", although some of his laws
encompassed several assertions that were later divided into
additional laws. The original seven as Ravenstein originally
set forth are as follows:
1) Most migrants only proceed a short distance, and
toward centers of absorption.
2) As migrants move toward absorption centers, they
leave "gaps" that are filled up by migrants from more remote
districts, creating migration flows that reach to "the most
remote corner of the kingdom."
3) The process of dispersion is inverse to that of
4) Each main current of migration produces a
5) Migrants proceeding long distances generally go by
preference to one of the great centers of commerce or
6) The natives of towns are less migratory than those of
the rural parts of the country.
7) Females are more migratory than males.
Ravenstein's laws immediately created a stir, with some
complaining that he had identified patterns of migration, but
that this was not the same as discovering "natural laws." Four
years, later, he presented another paper that looked at
migration patterns elsewhere in Europe and North America, in
which he highlighted an exception to migration patterns based
upon the American frontier experience. He noted that people
are more willing to travel long distances to occupy unsettled
land than they would in a country more fully settled, as was
the case in the United Kingdom.
Later social scientists would be more kind to Ravenstein's
legacy. Some recent reviews of his work credit him with as
many as eleven original migration laws. He is generally
credited with the origination of distance decay theories of
migration and spatial interaction, and later theories expanded
on "push" and "pull" factors of migration. Later studies by R.
Lawton in the 1950s and 1960s reused Ravenstein's methods but
added additional demographic indicators to arrive at refined