Demographic analysis (DA) is a term that refers to a set of methods that have been used to develop estimates of the population for comparison with the decennial census counts. The Census Bureau has been developing DA estimates as a tool for evaluating results from decennial censuses since the 1950 Census (Robinson 2011). DA estimates are developed primarily from historical vital statistics, estimates of international migration, and information on Medicare enrollment that are independent from the Census being evaluated. For DA in 2010, we developed a set of national-level estimates by age, sex, and race (Black/non-Black) for the total population and by Hispanic origin for the population under age 20. Upon completion, the DA estimates were compared with census counts; we plan to evaluate the differences by demographic characteristics.
One component of the DA estimates is net international migration (NIM), which represents the movement across the borders of the United States of people who change their residence. Although the NIM component in 2010 DA comprises approximately twelve percent of the total DA resident population under age 65, it represents a large portion of the uncertainty in the DA estimates. As with all components of the DA estimate, there were many assumptions and data limitations included in the calculation of NIM estimates that must be considered.
For DA in 2010, the population under age 65 was estimated using information on births, deaths, and international migration (cohort-component method) while the population 65 years and older was estimated using information on Medicare enrollment adjusted for under enrollment (Demographic Analysis Research Team 2010b). This paper will discuss the estimates of international migration for the population below age 65 on April 1, 2010 that were used as inputs to the five series of DA estimates that were publicly released on December 6, 2010. It will describe the different methods used to measure NIM for 2010 DA, focusing on estimates for the 2000 to 2010 time period.
One important aspect of the 2010 DA methodology is the calculation of multiple estimates of the resident population in the United States on April 1, 2010. The DA research team produced multiple estimates of births and estimates of net international migration which were combined to develop five series of estimates of the resident population. By calculating multiple estimates, we were able to understand how using different assumptions to compute subcomponents of NIM affects the total NIM estimate, and in turn the total DA estimate. In December 2010 we released the five series of DA estimates (low, low middle, middle, high middle, and high).
The NIM estimates for 2010 DA were built from the 2000 DA estimates. Estimates of migration flows from 2000 to 2010 were added to the base of pre-April 2000 NIM from 2000 DA. We estimated NIM from 2000 to 2010 as four subcomponents: foreign-born immigration, foreign-born emigration, net native migration, and net migration between the United States and Puerto Rico. This paper will provide an overview of the data and methods used to develop these four components of international migration. Additional working papers will be released that describe each component in more detail.