40 Years of Changing Demographics

New York Times reporter Stephen Farrell captured the dramatic demographic changes in southern Brooklyn over the past several decades with a video of mayoral candidate Sal Albanese visiting his "old neighborhood" in and around Bay Ridge and Bensonhurst.

When Albanese represented the area as a City Councilmember during the 1980s and '90s, the population was largely white, especially of Italian ancestry. The video uses iconic imagery from that era such as a clip of John Travolta in the 1977 film Saturday Night Fever ordering takeout from Lenny's Pizza. Lenny's is still there, but people of Italian descent across much of the community have left and been replaced by an influx of immigrants from China, Mexico, and other Asian and South/Central American countries.

These changes can be quantified from decennial Census counts, but mapping that data at the local (tract) level is challenging because tract boundaries and even tract numbers change on a decade-to-decade basis. But an important effort by researchers at Brown University to compile Census data from 1970 through 2010 and normalize it to 2010 tract boundaries -- the US2010 Project's Longitudinal Tract Data Base -- has made it far simpler to visualize and analyze the changes.

For example, see the two maps (pictured below) featured in the New York Times video at 1:40 in the clip. Using common tract geography, they show where the white population has dramatically decreased throughout Bensonhurst.




Without the "Longitudinal Tract Data Base" (LTDB) from Brown University's "US2010" project, mapping this data across several decades would have required allocating tract data from one census to another using local (block-level or even street-level) population counts and accounting for changes in tract numbering - not a trivial task. According to the LTDB documentation:

The continual change in geography between successive censuses is a major barrier for longitudinal analysis. Census tracts are fundamental enumeration units for the U.S. decennial censuses and their boundaries very often change over time. In every new census many tracts are split, consolidated, or changed in other ways from the previous boundaries to reflect population growth or decline. US2010 presents ... a Longitudinal Tract Data Base (LTDB) which provides public-use tools to create estimates within 2010 tract boundaries for any tract-level data (from the census or other sources) that are available for prior years as early as 1970.

The Longitudinal Tract Data Base spans the decennial censuses from 1970 through 2000 - which collected information on ancestry, income, and education as well as total population counts - and the American Community Survey (ACS) through 2010, which replaced the decennial "long form" after the 2000 Census.

The LTDB files do not contain every Census variable, but they include the main race/ethnicity characteristics, population by ancestry and age, income, poverty, education levels, and employment (including industry variables). Though database users need to be mindful of margins of error with ACS estimates, the Longitudinal Tract Data Base enables seamless mapping of demographic and socioeconomic patterns over the past four decades.

The NYC Department of City Planning's Population Division describes the recent demographic changes in and around Bensonhurst as follows:

White declines were large in these areas ... [while] the Asian population increased by 58 and 57 percent in Bensonhurst East and West, respectively. Growth in the Chinese population accounted for the bulk of Asian increases. Over 17,000 Chinese were added to the two Bensonhurst neighborhoods over the decade. In 2000, whites were in the majority; however, by 2010, this was no longer the case, with Asians making up over one third of the population.

These changes (between 2000 and 2010) were a continuation of a several-decades-long trend, which the LTDB enables us to capture visually.

Here are some other maps of the south Brooklyn area using LTDB data for 1980 and 2010, showing population of Italian ancestry...