The most important component of gentrification is capital, meaning that the most important variable in this analysis is per capita income. Mapping the change in per capita income deciles over time provides a clearer picture of the change taking place in tracts that may be gentrifying according to the cluster analysis. Deciles are an effective way to show meaningful change in per capita income because they rank each tract in the context of other tracts at the same time. Small changes in per capita income are not reflected in such a basic scheme.
Chicago’s waterfront area is characterized by tracts that have not changed in their per capital income decile at all from 1980 to 2000 and by those that have risen up to 9 deciles. The majority of tracts in the outer ring of the city have dropped anywhere from 1 to 9 deciles during this time.
Many of the tracts in New York City have not increased or decreased many deciles from 1980 to 2000, suggesting that the overall per capita income structure has remained fairly constant. In contrast to this general trend, several tracts in Hoboken and Brooklyn near Manhattan have increased up to 9 deciles during this time period.
Animated maps of the per capita income decile of each tract from 1980 through 2000 in Chicago and New York City provide an even deeper understanding of the way this variable has changed over time. In New York City, Manhattan has remained in the upper deciles while Brooklyn and the Bronx have stayed in the lower deciles. The change from low to high deciles in the Hoboken, Brooklyn, and Manhattan areas that were highlighted by change map is well illustrated here. The animated map of Chicagoan tracts underscores the general trend of an increase in per capita income deciles near the lakefront and a drop in per capita income deciles in the outer ring of the city. Both of these methods of mapping change effectively convey the same story—increasing per capita income in areas that show signs of gentrification.