Patterns of Immigration
to and from
the United States
This chapter presents the available data on the current volume of immigration to the United States and goes into considerable detail on the characteristics of immigrants. Before treating these topics, we look at the relationship between the flow of immigrants and the stock of immigrants as well as the relationship between the flow of immigrants and total population change during a particular period.
The flow of immigrants is defined as the number of foreign-born persons entering the nation as usual residents in a given period. The stock of immigrants is defined as the number of foreign-born persons in the nation at a given point in time. In large part the annual flows of immigrants determine the stock of immigrants at any one time. But two other factors, emigration and death, also determine the stock of immigrants. The best analogy to the stock of immigrants is that it represents the level of water in a bathtub in which both the faucet and the drain remain open. The flow of water into the tub represents the inflow of immigrants and the outflow into the drain represents the exits from the stock of immigrants caused by either death or emigration of the foreign-born. If you look back at Table 4.1, you can see that the stock of the foreign-born population of the United States increased uninterruptedly from 1790 to 1930. In that period the flow of immigrants was always greater than the number of foreign-born persons who either emigrated or died. From 1930 to 1970, however, the stock of foreign-born persons declined; during these decades the number of foreign-born persons who died or emigrated was consistently larger than the number of immigrants. Since 1970 the stock of immigrants has again risen. This implies that the immigrant flow has been greater than the outflow of the foreign-born.
Demographers like to utilize a concept known as the net immigration of the foreign-born. This is defined as the difference between the number of foreign-born persons who immigrate to the nation during a given period and the number of foreign-born persons who emigrate from the nation during the same period. Making use of this term, one can define the change in stock of the foreign-born population during a given time