Although the overall mobility rate has reflected, to a slight extent, some of the postwar changes in business conditions, it has not fluctuated very much in 13 successive annual surveys. The percentage of reported movers in the total population 1 year old and over has ranged from 18.6 to 21.0, with an average of 19.6, and has not shown any discernable trend. Intra-county mobility rates and intercounty migration rates also show no trend over the 13-year period.

Of the 174 million persons 1 year old and over who were loving in the United States in March 1960, 12.9 percent were living in a different house but in the same county as the one they had been living in a year earlier, 6.4 percent were living in a different county, and about 0.5 percent had lived abroad in 1959 (table 1).

The lack of trend in the mobility rates of the general population seems to be the result of offsetting trends within the white and nonwhite populations. The 12 annual observations by color reveal a slight downward trend in white intracounty mobility rate and little or no trend in white migration. For the non-whites, on the other hand, there has been an upward trend in the intracounty mobility rate and some indication of a downward trend in migration. The former trend has more than compensated for the latter, resulting in an upward trend in the overall mobility rate of nonwhites. These patterns are probably best explainable in terms of the large white movement from cities outward to suburban areas, and the resulting increase in the availability of alternative living facilities for nonwhites within cities and possibly also in the immediately adjacent areas. Although postwar trend of the nonwhite short-distance mobility rate has been upward as just stated, the 1959-1960 rate is below the average of the rates for preceding five years.

This fact may indicate that the mobility of nonwhites is still feeling the effects of the recent economic recession.

The mobility of the population encompasses a great variety of changes, which are not reduced to equivalent units even when we deal with a particular type of move such as interstate migration. Many moves are induced by economic factors, like taking a new job or going in search of a job; but others are associated with changes in marital status, health, and other personal reasons, and finally, many dependent wives and children move simply because the head of their family moves.

We cannot isolate form the available data those kinds of move that would be most responsive to secular and cyclical economic changes, but we can approximate such moves by studying separately those demographic groups which are more directly responsive to changes in the economy than other groups. For example, we might expect that a relatively high proportion of the moves of men 25 to 34 years old are in response to the job factor, whereas those of women 65 years old and over are more responsive to the general economic situation and to changes in social security programs. Over the 13-year old period, mobility rates do not show any trends for either group. The interstate migration rate of young adult men shows peaks at 1950-1951 and 1957-1958 and troughs at 1949-1950 and 1955-1957. To the extent that the rates for elderly women exhibit peaks and troughs, these occur in quite different years.