In the March 1956 survey, the information on mobility status of women 18 years old and over was cross-classified by marital status, age, and labor force status (table 5). There was some evidence

that women living with their husbands tended to be more mobile (20.1 percent) than other women (18.5 percent). The greater mobility of these women was attributable to their greater mobility in the age group 18 to 24 years, the years in which most women marry. In this age group, women living with their husbands were twice as mobile as other women of the same age (56.1 vs. 26.1 percent).

or

when both age and marital status are taken into account, differences in mobility between women in the labor force and women not in the labor force appear to be rather small. Furthermore, the direction of the difference varies. A larger sample the results of several annual surveys might well reveal some significant relationships between mobility status and labor force status among women, course. For example, the present data suggest that among single, widowed, divorced, and separated women in each age group, a larger proportion of those not in the labor force have recently migrated than of those in the labor force.

WORK EXPERIENCE IN 1955

of

The statistics in the foregoing section related to work status in the survey week in March 1956. For about half of the March sample, information on work experience in 1955 had been collected in the January 1956 survey (tables 6 to 9).

The highest migration rates for men 20 to 44 years old were found among those who worked in civilian jobs less than half the year or had not worked at all during 1955 (table 6). Men who worked at their jobs for the full year had the lowest migration rates. In this age group, school or college attendance, unemployment, or service in the Armed Forces are the main reasons why men do not work continuously at civilian jobs throughout the year. As has been indicated, the migration rates of men who are seeking work or who are in the Armed Forces tend to be above those of men who are regularly employed. In the age group 45 to 64 years, migration rates were highest for those who worked 26 weeks or less.

For women, those who worked the year round had the lowest migration rates. Otherwise, there seems to be no direct relation between weeks worked during the year and mobility.

The relationship between short-distance mobility (intracounty movement) and work experience was not always the same as that between migration (intercounty movement) and work experience. For example, men 20 to 44 years old were more likely to have moved within a county if they had worked in 1955 than if they had not--14.5 and 4.8 percent, respectively.

In almost all of the statistics published by the Bureau of the Census relating population mobility to occupation or industry, these economic characteristics have related to the time of the survey; in other words, they have been characteristics of workers after their moves have taken place.1 Mobility may be more closely associated with the type of job before movement than with the type of job after movement, however. Furthermore, there is interest in changes in job characteristics that take place as a result of migration and of short-distance moves. Some data that partially meet these analytical needs are available from the combining of the March 1956 data on mobility with the January 1956 data on work history in 1955, for the same persons. The move could have taken place at any time between March 1955 and March 1956. We do not have here a description of jobs in March 1955, or prior to moving; but we do have the longest job held in 1955. Since the mean date of moving is roughly September 1955, the longest job in 1955 for movers is probably, in a majority of cases, the job held before moving.

entitled "Characteristics by Size of Place," "Education," and "Institutional Population" present statistics on mobility status in relation to the main subject of the report.

DEFINITIONS AND EXPLANATIONS

Population coverage.--The data for 1956 (covering the period March 1955 to March 1956) shown in this report relate primarily to the civilian population of the United States 1 year old and over. Approximately 872,000 members of the Armed Forces living off post or with their families on post were also included, but all other members of the Armed Forces were excluded. For simplicity, the group covered is called the "population" or the "civilian population" in this report. The coverage of the population for the earlier survey years was essentially the same. The data from the 1950 Census relate to the total population 1 year old and over.

Urban and rural residence.--The definition of urban and rural areas which was used in the March 1956 survey was the same as that used in the 1950 Census, but it differed substantially from that used in surveys and censuses before 1950. The territory classified as urban is the same as that in the 1950 Census.

Size of place.--The urban population is classified as living in urbanized areas or in urban places outside urbanized areas. According to the definition used in the 1950 Census and in the March 1956 Current Population Survey, the population in urbanized areas comprises all persons living in (a) cities of 50,000 inhabitants or more in 1940 or according to a special census taken between 1940 and 1950; and (b) the densely settled urban fringe, including both incorporated and unincorporated areas, surrounding these cities. Residents of urbanized areas were classified according to the size of the entire area rather than by the size of the place in which they lived. The remaining urban population is classified as living in the smaller urban places not in the urbanized areas.

Farm and nonfarm residence.--The rural population is subdivided into the rural-farm population, which comprises all rural residents living on farms, and the rural-nonfarm population, which comprises the remaining rural population. The method of determining farm and nonfarm residence in the March 1956 survey is the same as that used in the 1950 Census and in the April 1951 through 1955 and March 1950 Current Population Surveys but differs from that used in earlier surveys and censuses. Persons on "farms" who were paying cash rent for their house and yard only were classified as nonfarm; furthermore, persons in institutions, summer camps, "motels," and tourist camps were classified as nonfarm.

Standard metropolitan area. --Except in New England, a standard metropolitan area is a county or group of contiguous counties which contains at least

In the classification three main categories are distinguished:

1. Mobile persons or movers.--This group consists of all persons who were living in a dif

ferent house in the United States at the end of the period than at the beginning of the period.

2. Nonmobile persons or nonmovers.--This group consists of persons who were living in the same house at the end of the period as at the beginning of the period.

3. Persons abroad.--This group consists of persons, either citizens or aliens, whose place of residence was outside continental United States at the beginning of the period, that is, in a Territory or possession of the United States or a foreign country. These persons are distinguished from movers, who are persons who moved from one place to another within continental United States.

Mobile persons are subdivided in terms of type of mobility into the following two groups:

1. Same-county (intracounty) movers.--These are persons living in a different house but in the same county at the beginning and end of the specified period.

2. Migrants, or different-county (intercounty) movers.--This group consists of persons living in a different county in the United States at the beginning and end of the period. Migrants are further classified by type of migration on the basis of a comparison of the State of residence at the end of the period with the State of residence at the beginning of the period:

a. Migrants within a State.
Migrants between States.

b.

Age.--The age classification is based on the age of the person at his last birthday.

Color.--The term "color" refers to the division of population into two groups, White and nonwhite. The group designated as "nonwhite" consists of Negroes, Indians, Japanese, Chinese, and other nonwhite races.

Employment status

Employed persons.--This

category comprises those persons who, during the survey week, were either (a) "at work"--those who did any work for pay or profit, or worked without pay for 15 hours or more on a family farm or business; or (b) "with a job but not at work"--those who did not work and were not looking for work but had a job or business from which they were temporarily absent because of vacation, illness, industrial dispute, bad weather, or layoff with definite instructions to return to work within 30 days of layoff. Also included are persons who had new jobs to which they were scheduled to report within 30 days.

Unemployed persons.--This category includes those persons who did not work at all during the survey week, and who were looking for work. Also included as unemployed are persons who would have been looking for work except that (a) they were temporarily ill, (b) they expected to return to a job from which they had been laid off for an indefinite period, or (c) they believed no work was available in their line of work or in the community.

Labor force.--This category comprises (a) the total of all civilians classified as employed or unemployed in accordance with the criteria described above, and (b) persons serving in the Armed Forces who, at the time of the survey, were living off post or with their families on post. Members of the Armed Forces living on post, apart from their families, are not included.

Not in labor force.--This category includes those persons 14 years old and over. not classified as employed, unemployed, or in the Armed Forces. Persons who were engaged in "own home" housework, in school, inmates of institutions, retired, permanently unable or too old to work, seasonal workers for whom the survey fell in an "off" season, and the voluntarily idle are considered as "not in the labor force." Persons doing only incidental unpaid (less than 15 hours) are also classified as not being in the labor force.

work

Marital status.--The marital status classification identifies four major categories: Single, married, widowed, and divorced. These terms refer to the marital status at the time of enumeration.

The category "Married" is further divided into "married, spouse present," "separated," and "other married, spouse absent." A person was classified as

"married, spouse present" if the husband or wife was reported as a member of the household even though he or she may have been temporarily absent on business or on a vacation, visiting, etc., at the time of the enumeration.

For the purposes of this report the group "married, spouse present" is shown separately and the remaining groups are consolidated into "other marital status."

Work experience in 1955.--In the Current Population Survey for January 1956, information was obtained on the work experience in calendar 1955 of civilians 14 years old and over. Included in the information obtained were such items as number of weeks worked in civilian employment, amount of working time lost because of unemployment, and major occupation group of longest job held in 1955. For the purposes of this survey, service in the Armed Forces in 1955 was not considered as part of a person's work experience.

Approximately one-half of the households included in the January survey were also in the March 1956 survey, when information was obtained on mobility status and current labor force status. Information on those persons 20 to 64 years old who were reported as living in the same house in both January and March was matched to obtain cross-classifications of mobility status and current labor force status with work experience in 1955. The relatively small number of persons in this age group who were reported as abroad in March 1955, however, was excluded from the match.

Major occupation group.--The data on occupation for March 1956 relate to job held during the survey week. Persons employed in two jobs or more were reported in the job at which they worked the greatest number of hours during the week. The data on occupation shown in table 9 relate to the civilian job at which the person worked the greatest number of weeks during 1955. The Occupational categories shown are largely the major occupation groups used in the 1950 Census of Population. The composition of these major groups in terms of detailed occupations is shown in Volume II of the reports of the 1950 Census. One major occupation group--menagers, officials, and proprietors, except farm--is subdivided into salaried workers and self-employed workers. The category "Service workers" represents a combination of the two categories "Private household workers" and "Service workers, except private

household."

Number of different jobs held in 1955.--The information on number of jobs held in 1955 relates to the number of full-time or part-time jobs held in civilian employment during the year. It was not possible to distinguish between those persons who held two jobs or more simultaneously and those who held two jobs or more in sequence. A person who had for example, and

a full-time job throughout 1955,

also did some part-time work during the year was classified as having two jobs or more. The extent to which this prevailed in 1955 is not known; however, in 1955 about 3 million persons held two jobs or more simultaneously at least part of the year.

Percentages. --Percentages are shown as calculated; therefore, they do not always add to exactly 100.0 percent. The totals, however, are always shown as 100.0 percent.

SOURCE AND RELIABILITY OF THE ESTIMATES

The estimates presented in this report are based on data obtained in connection with the monthly population sample survey of the Bureau of the Census. The statistics for March 1956, April 1955, and April 1954 are based on a sample design instituted in January 1954. This sample was spread over 230 sample areas comprising 453 counties and independent cities. A total of 24,000 to 26,000 dwelling units and other living quarters were designated for the sample at any time, and completed interviews were obtained each month from about 20,000 to 22,000 households. Of the remainder, about 500 to 1,000 were households for which information should have been obtained but was not, and the rest were vacant households or those otherwise not to be enumerated for the survey. The data for all previous periods for which similar information was obtained from the Current Population Survey were based on a different sample, which consisted of about the same number of units but which covered only 68 sample areas in 42 States and the District of Columbia.

The estimating procedure used in this survey involved the inflation of weighted sample results to independent estimates of the civilian noninstitutional population of the United States by age, color, and sex. For the March 1956, April 1955, 1954, and 1953 figures shown in this report, the independent estimates used were based on statistics from the 1950 Census of Population; statistics of births, deaths, immigration, and emigration; and statistics on the strength of the Armed Forces and separation records. For April 1952 and earlier years, the independent estimates were based on data

of the 1940 Census of Population similarly adjusted to take account of the aging of the population, births, deaths, net immigration, and changes in the size of the Armed Forces.

a sample they The following

Since the estimates are based on are subject to sampling variability. illustration indicates the order of magnitude of the sampling errors for some typical statistics in March 1956. An estimated 3,046,000 employed males

25 to 34 years of age were living in different homes from the ones they had lived in a year ago. This number is 29.5 percent of the total number of employed males in this age group. The relative sampling error is about 6 percent of the estimate of 3,046,000. The sampling error of the estimate of 29.5 percent is about 2 percentage points. The chances are about 68 out of 100 that the estimates from the sample differ from the results which would be obtained from a complete census by the sampling errors indicated for the above items. The chances are about 95 out of 100 that the differences would be less than twice the specified sampling errors and about 99 out of 100 that they would be less than 2 times the errors indicated.

The data presented in tables 6, 7, 8, and 9 come from those households which were interviewed in January 1956 for work experience information and again in March 1956 for information relating to the mobility of the population of the United States. Since only 50 percent of the sample of households in January were scheduled for interview in March, these data are subject to some what greater sampling variability than those in tables 1 to 5 and 10 to 11. In addition, since some of the households scheduled for interview in both months were not interviewed in either January or March, the matched data are subject to somewhat greater bias due to noninterview than those based on one month's enumeration.

The following illustration indicates the order of magnitude of the sampling errors from estimates made from the matched data. An estimated 12.4 percent of the men in the age group 20 to 44 who did not work at all in 1955 were classified as migrants. The sampling error of the estimate of 12.4 percent is about 2 percentage points.

Table

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10

11

14 years old and over, by mobility

12