The statistics on State of birth are of value mainly for the information they provide on the historic movements of the native population from one State to another within the United States from the time of birth to the date of the census. Extreme care should be exercised in the use of the statistics as representing or measuring migration, however, since in this connection they indicate only the net result of migration during the differing periods of the life of the persons enumerated.

The census figures on State of birth reflect the migration of only those persons who have moved from one State to another and are, on the date of the census, living in States other than those in which they were born. The statistics, therefore, afford no indication of the amount of migration within a given State from rural to urban communities or from one locality to another; nor do they take any account of intermediate moves between the time of a person's birth and the time of the census.

The statistics thus do not indicate the total number a persons who have moved from the State in which they were born to other States, or to any specific State, during any given period of time. Some of those who had gone from one State to another have since died others have returned to the State in which they were born, and others have gone to still other States, or to places outside the United States.

The net gain or loss through interregional movement (tables 5 and 16) interdivisional movement (tables 6, 7, 8, and 17), or interstate movement (tables 11 to 14) represents the difference in the census data between the total number of surviving native persons who had moved out of the specified area since they were born and the total number of surviving native persons who had moved into the specified area since they were born. Some of these persons are the survivors of groups who departed from or arrived in the area half a century or more before the census date. The figures, therefore, do not represent migration in the sense of the number of persons coming or going during the previous census decade or during any other specific period of time. The "change in net gain or loss as compared with the previous census," as shown in the final column of table 7, represents the algebraic difference between the net gains or losses at the beginning and end of the decade. Even this figure, however, does not represent exactly the difference between the number of native migrants out of the region and the number of native migrants into the region, since it is affected also by differences in mortality and by the movement of the native population between the area in question and foreign countries.

Although it is not possible to estimate migration during a given decade from statistics on State of birth, it is possible to make such estimates from other census statistics. Specifically, net migration for a given Stats, or other area, for a given inter-censal decade can be estimated relative to all other areas combined. Such estimates may also be made by age, sex, race, and nativity. Very briefly, the procedure consists of starting with the population in a given State at a particular census, allowing for mortality during the decade, and subtracting the numbers of estimated survivors from the corresponding population enumerated in the State at the next census. The Census Bureau has published estimates by this so-called "residual method" by States for the period 1950 to 1960 in Current Population Reports, Series P-25. (See for example Nos. 227 and 247.) Estimates for counties, State economic areas, etc., are published in Current Population Reports. Series P-23, No. 7.

The present report is the second to present State- of-birth data cross-classified by fairly detailed age distribution. These data give somewhat more information on the time of migration than the data shown for earlier censuses. With the use of appropriate mortality rates, one can compute, for example, from the number of persons 20 to 29 years old living in California in 1950 but born in another State, the number expected in the same category 30 to 39 years old in 1960 had there been no further in-migration during the decade. A comparison of the expected and observed numbers for 1960 will indicate the approximate in- migration to California in this age cohort during the decade, If in-migrants during the decade are defined as those who came into the State during the decade and were still living there at the end of the decade. The chief source of error in this approximation is the departures of former In-migrants. Similarly, fairly good estimates can be made of the total out-migrants from a given State to all other States and of the net migration. Using the figures on the number born and still living in the same State at successive censuses, one can also identify the age groups in which there has been further net out-migration during the decade and those In which there has been net return migration.

State of birth statistics by age at successive censuses yield much less accurate estimates, however, of particular streams of migration during the decade. Consider, for example, the 1950-1960 migrants from New England to California. The additional complication here is that one does not know whether the decennial increment in the New England-born represents persons who left New England during the decade or whether it represents persons who left New England prior to 1950 and were living in a third area in 1950 - Iowa, for example. The only exception is the case of the children under 10 years old at the time of the latest census, who obviously left their birthplace during the most recent decade.

For persons who are living in a different State from the State of their birth, the data Indicate whether the interstate move occurred between contiguous or noncontiguous States. States have been classified as contiguous if their boundaries touch at any point.<sup>1

1</sup>The following is a list of the contiguous States for each State:

Alabama	Fla., Ga., Miss., Term.
Alaska	None
Arizona	Calif., Colo., Nev., N. Mex., Utah
Arkansas	La., Miss., Mo., Okla., Tenn., Texas
California	Ariz., Nev., Oreg.
Colorado	Ariz., Kans., Nebr., N. Mex., Okla., Utah, Wyo.
Connecticut	Mass., N.Y., R.I.
Delaware	Md., N.J., Pa.
Dist. of Col.	Md., Va.
Florida	Ala., Ga.
Georgia	Ala., Fla., N.C., S.C., Tenn.
Hawaii	None
Idaho	Mont., Nev., Oreg., Utah, Wash., Wyo.
Illinois	Ind., Iowa, Ky., Mo., Wis.
Indiana	Ill., Ky., Mich., Ohio
Iowa	Ill., Minn., Mo., Nebr., S. Dak., Wis.
Kansas	Colo., Mo., Nebr., Okla.
Kentucky	Ill., Ind., Mo., Ohio, Tenn., Va., W.Va.
Louisiana	Ark., Miss,, Texas
Maine	N.H.
Maryland	Del., D.C., Pa., Va., W.Va.
Massachusetts	Conn., N.H., N.Y., R.I., Vt.
Michigan	Ind., Ohio, Wis.
Minnesota	Iowa, N. Dak., S. Dak., Wis.
Mississippi	Ala., Ark., La., Tenn.
Missouri	Ark., Ill., Iowa, Kans., Ky.,Nebr., Okla., Tenn.
Montana	Idaho, N. Dak., S. Dak., Vyo.
Nebraska	Colo., Iowa, Kans., Mo., S. Dak., Wyo.
Nevada	Ariz., Calif., Idaho, Oreg., Utah
New Hampshire	Maine, Mass., Vt.
New Jersey	Del., N.Y., Pa.
New Mexico	Ariz., Colo., Okla., Texas, Utah
New York	Conn., Mass., N.J., Pa., Vt.
North Carolina	Ga., S.C., Tenn., Va.
North Dakota	Minn., Mont., S, Dak.
Ohio	Ind., Ky., Mich., Pa., W.Va.
Oklahoma	Ark., Colo., Kans., Mo., N. Mex., Texas
Oregon	Calif., Idaho, Nev., Wash.
Pennsylvania	Del., Md., N.J., N.Y., Ohio, W.Va.
Rhode Island	Conn., Mass.
South Carolina	Ga., N.C.
South Dakota	Iowa, Minn., Mont., Nebr., N. Dak., Wyo.
Tennessee	Ala., Ark., Ga., Ky., Miss., Mo., N.C., Va.
Texas	Ark., La., N. Mex., Okla.
Utah	Ariz., Colo., Idaho, Nev., N. Mex., Wyo.
Vermont	Mass., N.H., N.Y.
Virginia	D.C., Ky., Md., N.C., Tenn., W.Va.
Washington	Idaho, Oreg.
West Virginia	Ky., Md., Ohio, Pa., Va.
Wisconsin	Ill., Iowa, Mich., Minn.
Wyoming	Colo., Idaho, Mont., Nebr., S. Dak., Utah

The information on place of birth is used to classify the population into two major groups: Native and foreign born.

The foreign-born population is combined with the native population of foreign or mixed parentage in a single category termed the "foreign stock." This category comprises all first and second generation Americans. Third and subsequent generations are described as "native of native parentage." Age data for the total foreign stock are presented in this report in table 14; all other data for the foreign stock are classified by nativity.

In this report, persons of foreign stock are classified according to their country of origin, with separate distributions shown for the country of birth of the foreign born and the parents' country of birth for the native of foreign or mixed parentage. Native persons of foreign parentage whose parents were born in different countries are classified according to the country of birth of the father.

The question on place of birth and parents' birthplace specified that country of birth be reported according to international boundaries as recognized by the United States at the time of the census. (See excerpt from questionnaire above.) Because of the many changes in boundaries that have occurred over the past hundred years in the areas from which the major segment of the foreign stock _have emigrated, it is reasonable to expect that these instructions may not have been followed in all instances. Some misreporting of place of birth by persons ignorant of boundary changes, as well as by persons of illegal immigration status, most likely exists. Although no specific evidence can be cited for 1960, on the basis of data from the Post Enumeration Survey for 1950, it was estimated that the same country of- birth was obtained in the census and the survey for approximately 90 percent of the foreign-born persons properly included in the 1950 Census.

Table B. Median Age of the Foreign Born, for the United States, 1960, and of the Foreign-Born White, for Conterminous Untied States, 1950 and 1940, By Selected Country of Origin

Country of birth	Total foreign born, 1960		Foreign-born white
	Median age	Percent white	1950	19401
Total	257.2	95.4	56.1	50.9
United Kingdom	56.8	99.7	356.9	53.9
Ireland	59.3	99.9	58.3	54.7
Norway	64.8	100	61.8	56.3
Sweden	67.5	99.9	63.6	58.0
Germany	52.8	99.7	57. 3	56.6
Austria	63.5	99.9	58.4	51.1
Poland	62.2	99.9	57.5	49.9
Czechoslovakia	62.6	99.9	58.5	52.2
Hungary	60.4	99.9	(4)	50.9
Yugoslavia	58.7	99.9	(4)	50.0
Lithuania	65.6	99.9	(4)	51.8
Finland	66.5	99.9	(4)	53.2
U.S.S.R	62.9	99.8	557.5	49.4
Italy	60.8	99.956.5	48.8
Canada	50.4	98.9	49.6	69.5
Mexico	42.8	99.4	44.0	40.3

In this century, nativity and parentage data have been available for the total population from the 1900 and 1960 Censuses only; for intervening censuses, tabulations were made for only the white population. In order to permit historical comparisons, a number of tables in this report are shown for both the total and the white population.

Historically most of the immigrants to the United States were from European countries, and, therefore, only a small proportion of the immigrants were non-white. With the decline in immigration this situation has been changing, as is reflected in the increasing proportion of nonwhites in the foreign-born population (table C).

Table C. Foreign-Born Population, Total and Nonwhite, For Conterminous United States: 1900 To 1960

Census year	Total	Nonwhite
		Number	Percent
1960	9,661,028	381,709	4.0
1950	10,347,395	251,980	2.4
1940	11,594,896	175,758	1.5
1930	14,204,149	220,744	1.6
1920	13,920,692	207,938	1.5
1910	13,515,886	170,341	1.3
1900	10,341,276	127,459	1.2

Besides the inclusion of the foreign nonwhite stock, there are other inconsistencies between 1960 and earlier censuses. The general method of processing the returns for country of origin was the same for the 1950 and 1960 Censuses; however, a slight variation was introduced in the handling of entries of Austria-Hungary. In 1950, the technique of assigning a specific country for entries of Austria-Hungary depended on the surname. In 1960, a question on mother tongue was asked of all foreign-born persons and the allocation to a specific country was made on the basis of the language reported. For example, persons reporting Rumanian were classified as born in Rumania. For blanks on mother tongue, a system was devised to allocate the entries of Austria-Hungary in the coding operation on the basis of the distribution of nationalities of migrants from the Austro-Hungarian Empire as reported in the 1920 Census report, Volume II, Population. It appears that, as a result of these revisions in the coding procedures, the apparent understatement in the number of persons of Yugoslavian origin, which was evident in the data for 1950, does not exist in the published 1960 statistics. The change in the method of processing entries of Austria-Hungary combined with the improvements resulting from self- enumeration may have been responsible for the better coverage. (For additional information on these data see the text in Volume I, Characteristics of the Population, Part 1, United States Summary.)

The distinction between Canada-French and Canada- Other was not maintained in the collection and publication of 1960 data on country of origin. Data for 1960 for persons of Canadian origin are comparable with the sum of the categories Canada-Other and Canada-French from earlier censuses.

Prior to 1950, questions on citizenship and mother tongue were used, when feasible, to assign entries on nativity and country of origin where these entries were omitted or uncodable. In the 1950 Census the question on mother tongue was excluded; in 1960, this question was asked of the foreign born, but citizenship was not asked. Data for 1960 on mother tongue are to be presented in the forthcoming report PC(2)-1E, Mother Tongue.

The classification by country of origin appears to be consistent with the expected values based on an examination of past censuses. In countries where the same boundaries have been maintained over a long period of time, the classification by country of origin appears to be reasonable.

The data seem to indicate that a completely accurate count of the foreign stock from areas in which there had been considerable boundary changes after World War I may not have been achieved. An example of such a problem is found in the reporting of Austria- Hungary as place of birth. A discussion of the technique designed to handle such entries is given above in the section on "Comparability of the data."

Changes from 1940 to 1950 and from 1950 to 1960 in the foreign stock from Ireland (Eire), Northern Ireland, and, consequently, the United Kingdom seem to reflect errors in reporting rather than actual changes in the numbers in each category. Because of the omission from the schedule of any instruction to distinguish Northern Ireland and Ireland (Eire) in 1950, the number of persons of foreign stock from Northern Ireland was apparently underreported to a considerable degree in that census and that from Ireland, correspondingly overreported. The reinstated special caution relating to this point on the 1960 questionnaire resulted in a very different and probably more correct distribution between the two countries. The foreign born from Northern Ireland increased by 340 percent and those from Ireland decreased by 33 percent between 1950 and 1960. Similar changes occurred for native persons of Irish parentage. The decline in the foreign stock from the United Kingdom between 1950 and 1960 undoubtedly would have been greater had it not been affected by the spurious increase in the figure for Northern Ireland.