Stock data is used to estimate the number of individuals of a certain population of interest at a specific point in time.
For example: The number of naturalized Colombian immigrants residing in the U.S as of July 2013.
Sources of Stock data
American Community Survey
Annual survey conducted by the census bureau. Replaced the Decennial Census long form in 2000. Since 2007 you can find the ACS with multiyear sampling estimates. More information.
Coverage/Frequency: 2000-Present; every year
Social Explorer: Interactive visualization tool that utilizes the decennial censuses and American Community Survey data, includes download.
American Fact Finder: Access to 2000 and 2010 decennial censuses, the American Community Survey, and the Economic Census.
IPUMS (microdata): More than fifty high-precision microdata samples of the American population drawn from fifteen federal censuses and from the American Community Surveys.
Composed of short form (basic) and long form (socio-economic). Long form replaced by ACS in 2010.
Coverage/Frequency: 1790-2010; every 10 years
Access: Social Explorer, American Fact Finder, IPUMS (microdata)
Special access: IPUMS Microdata prepared by Professor Marrow
Estimates of the Unauthorized Immigrant Population Resident in the United States: January 2011- Department of Homeland Security (DHS)
Report providing estimates of the size of the unauthorized immigrant population residing in the U.S
Flow data is an estimate of change (addition/subtraction) of a population of interest at a specified period of time.
For example: The estimate of the number of persons arriving to the U.S from Vietnam for the years of 1965-1975.
Sources of Flow Data
Yearbook of Immigration Statistics- Department of Homeland Security (DHS)
Admissions on permanent basis, temporary basis, asylum or refugee status, naturalizations. Replaced the functions of the INS in 2001
Coverage/Frequency: 2002-Present; Every fiscal year
Statistical Yearbook of the Immigration and Naturalization Service (INS)
Admissions on permanent basis, temporary basis, asylum or refugee status, naturalizations. Pre-DHS.
Coverage/Frequency: 1996-2001; Every fiscal year
Older coverage: HathiTrust Digital Library (1978,1980-1984,1987, 1995, 1997, 1998)