In order to measure the magnitude and direction of the correlations between the examined variables we run simple linear regression models. The linear model’s dependent variable is median income of each year in PUMA level (1990, 2000, and 2010) and independent variable is income entropy index (income integration level). This result corresponds to Figure 7, 8 and 9. Dash lines in the figures indicate median income level of NYC and it reveals neighborhood which is located nearby the median income line has higher income integration level. One interesting trend is revealed that neighborhoods that has higher than median NYC income didn’t change a lot in integration level over two decades. By contrast, neighborhoods that has lower than median NYC income have been clustered to higher integration level.
Observing the change of Median Income over Income integration through the 20 years we understand that the trend in NYC, unlike the deepening of economic segregation in the country (Fry & Taylor, 2012; Pendall, & Carruthers, 2010), is towards more and more integrated by income neighborhoods. Though we do not have the consequences of the situation in the US, here we see the neighborhoods’ polarization to highly integrated and highly segregated, and the economic gap that enlarged along with this process.
Rent Growth over Income Integration
The last part of the regression models’ analysis was to assess the correlation between Rent growth and Income Integration level. The models demonstrated low correlations, which made us define the richest PUMAs as outliers that were about to be excluded from the analysis.
The outliers were defined by exceeding two standard deviation from the mean of the Median Family Income. The reason for excluding only one-tail outliers was that these neighborhoods are too rich to be considered as taking part in the city’s urban renewal processes. Figures 11 and 12 shows the change in median rent per PUMA, between 1990 and 2000 and between 2000 and 2010. The level of income is revealed as four groups varied by color: red for the poorest PUMAs, light-red for poor PUMAs, light-blue for relatively rich and blue for the richest PUMAs.