For the United States approximately 7 percent of the foreign-born population did not report mother tongue. Failure to report a language may have resulted from a number of causes. For example, in some situations, the respondent and the enumerator may have thought the mother tongue was obvious from the country of birth. Furthermore, since the mother-tongue question was asked only of foreign-born persons, It was asked relatively rarely in some areas and may have been overlooked by the enumerator. It is apparent that in areas where there are large concentrations of foreign-born persons, nonresponse rates are substantially lower than in areas where there are relatively few such persons.
The statistics on mother tongue in this report differ from those published in Volume I because of a different procedure used for the tabulation of non- responses for mother tongue. In Volume I, all non- responses were shown as a separate category. In this report, allocations of mother tongue were made for some nonresponses on the basis of the country of birth of the individual. The basic procedure involved the use of data from the 1940 and 1930 censuses which showed that in 12 countries; over 90 percent of the foreign-born population had reported the same mother tongue. For 1960, nonresponses on mother tongue for persons born in these 12 countries were allocated to the major language of the country. This procedure accounted for the allocation of almost half of all the nonresponses, leaving 3.9 percent of the foreign-born population in the category "mother tongue not reported." (See table A and appendix table A-1.)
Table A. Allocations for Nonresponse by Mother Tongue: 1960
||Total after allocation
||Percent of total
|Total foreign born
In 1940, no attempt was made to allocate mother tongue for those persons not reporting; in preceding censuses, persons not reporting mother tongue were allocated to a specific mother tongue if the persons originated in a country from which immigrants had reported, in the main, a single mother tongue.