Immigration data and national population estimates for the United States

The immigration component in national population estimates is comparatively small, but it is not insignificant and may indeed be an important source of error. Therefore, it warrants the considera-tion of those concerned with population estimates. The paper considers alternative methods for deriving estimates of immigration from the raw data and presents estimates of net immigration from 1950 to 1965. They are developed from estimates previously published by the Bureau of the Census, but they differ at some points where new data have become available or where a review of the data has led to a change in judgment on how best to use them. The paper also presents suggestions on how immigration statistics might be altered for purposes of improving the estimates.Census data may be used to estimate net immigration by three different methods, but upon analysis each method proves to be inadequate. Hence, data based on visas surrendered at the port of entry must be the principal source of immigration estimates. These data have their limitations because (1) they do not cover net arrivals of citizens from abroad and from Puerto Rico, (2) they do not report departures of aliens, and (3) they do not allocate all immigrants to year of entry. Alien registration and passenger data offer possible alternative estimates.The paper attempts to measure unrecorded immigration, discusses how net arrivals of citizens from abroad and from Puerto Rico may be estimated, and how the age, sex, and race of immigrants may be treated.