Introduction

Gentrification is one variant of neighborhood change that has been used by researchers, policymakers, planners, and activists as a catchall for a litany of positive and negative neighborhood-level changes. This growing list of “gentrification-associated-indicators” has empirically devalued the term since any or all changes in a neighborhood can implicate gentrification. Yet the original conceptualization of gentrification—by Ruth Glass in 1964—observed a simple change in working-class neighborhoods’ socioeconomic status. Therefore, I start with this original conceptualization to conduct an empirical validity test of the neighborhood-level indicators often associated with gentrification.

Methods and Data

The analysis is divided into three distinct parts: (1) the creation of a novel measure of neighborhood-level socioeconomic status (SES) over a five-year period and the identification of low-SES neighborhoods, (2) the extraction of random effects coefficients to capture the five-year slope of change in both the novel SES measure and various demographic, economic, and physical attributes of a neighborhood, and (3) spatial autoregressive (SAR) models that detail how the change in each neighborhood’s SES acts as a predictor to other neighborhood changes historically associated with gentrification.

Data for this analysis were obtained from consecutive five-year estimates of the 2014 through 2018 U.S. Census Bureau’s American Community Surveys and administrative building permits data from the City of Boston, MA and the City of Philadelphia, PA – the former curated by the Boston Area Research Initiative (BARI) and the latter by OpenDataPhilly.

The Creation of a Neighborhood-Level Socioeconomic Status (SES) Score

To capture a neighborhood’s SES score, factor loadings were extracted from a reflective factor analysis that included census-tract-level estimates of median household income, occupational prestige, median home value of owner-occupied housing units, and educational attainment. These loadings were extracted for each individual year between 2014 and 2018 and serve as a proxy measure of each census tract’s SES level during the given year. Box plots of these neighborhood socioeconomic scores for each city are detailed in Figure 1.

FIGURE 1

Figure 2 illustrates how each census tract’s SES scores compares with the mean SES score of the city in each given year. Tracts with a “low” SES score were below the city’s mean SES score for the given year. Tracts with an “average” distinction scored at or above the mean SES score for the given year but below one standard deviation above the mean. “High” SES tracts scored at or above one standard deviation above the city’s mean SES score for the year while “Very High” tracts score above two standard deviations from the city’s mean.

Results from these neighborhood-level SES scores were colloquially reflective of wealthier and low-income areas within both cities. The measure also reflected racial and ethnic residential divisions within both cities. While every census tract’s SES score changed per year, most tracts remained within their “very high,” “high,” “average,” or “low” category for all five years with only a few examples of intermobility.

FIGURE 2

Boston

Philadelphia

The Extraction of Random Effects Coefficients

A mixed-effects model was used to extract the “random effects” coefficients (i.e., the slopes) of each census tract’s SES score during the five-year period. These slopes represent the individual trajectories of each of the tract’s SES scores during the five-year period. The range in SES slopes for each city’s census tracts are summarized below in figure 3.

FIGURE 3

Boston

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##  -10011   -2838   -1177       0    1759   34018

Philadelphia

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
## -6922.6 -1465.1  -823.4     0.0   222.7 27584.5

In addition to the change in SES, a series of neighborhood-change-indicators (traditionally aligned with theories and analyses of gentrification) were identified from the consecutive five-year estimates of the 2014 through 2018 American Community Surveys and administrative building permit records. Mixed-effects models were also used to individually extract the random effects of each neighborhood change indicator. For example, each tract had an individual percentage of residents aged 25-to-34-years-old that altered from 2014 to 2018. Thus, a mixed effects model using a beta regression (ideal for working with continuous dependent variables that ranges from 0 to 1) was used to extract estimated slopes per tract of the percent of age 25-to-34-year-old residents. Different mixed effects regression models were used based on the structure and normality of each variable. Summarized lists of each variable, the type of mixed effects regression used, and a summary of its slopes are listed below in Figure 4 for Boston and Figure 5 for Philadelphia.

FIGURE 4

Boston

##     Tract ID                SES         Total Population  Total Housing Units
##  Min.   :25025000100   Min.   :-10011   Min.   :-203.22   Min.   :-59.96814  
##  1st Qu.:25025040801   1st Qu.: -2838   1st Qu.: -61.18   1st Qu.:-17.65016  
##  Median :25025081001   Median : -1177   Median : -12.97   Median : -7.55449  
##  Mean   :25025071948   Mean   :     0   Mean   :   0.00   Mean   : -0.00001  
##  3rd Qu.:25025100603   3rd Qu.:  1759   3rd Qu.:  43.52   3rd Qu.:  5.84975  
##  Max.   :25025140400   Max.   : 34018   Max.   : 388.78   Max.   :305.78686  
##  White (Non-Hispanic) Black (Non-Hispanic) Asian (Non-Hispanic)
##  Min.   :-1.9397983   Min.   :-3.763893    Min.   :-3.926957   
##  1st Qu.:-0.6153975   1st Qu.:-0.570648    1st Qu.:-0.920746   
##  Median : 0.0174486   Median : 0.010599    Median :-0.055191   
##  Mean   :-0.0000887   Mean   :-0.001561    Mean   :-0.005954   
##  3rd Qu.: 0.4885818   3rd Qu.: 0.579948    3rd Qu.: 0.924353   
##  Max.   : 3.1483432   Max.   : 2.762026    Max.   : 5.886387   
##  Latinx/Hispanic      Age Under 18          Age 18-24        
##  Min.   :-2.288420   Min.   :-1.4803396   Min.   :-2.185750  
##  1st Qu.:-0.630131   1st Qu.:-0.3683921   1st Qu.:-0.497492  
##  Median :-0.135919   Median :-0.0097002   Median :-0.007694  
##  Mean   :-0.004897   Mean   :-0.0000658   Mean   : 0.001295  
##  3rd Qu.: 0.478470   3rd Qu.: 0.2976563   3rd Qu.: 0.569963  
##  Max.   : 4.135858   Max.   : 1.9609984   Max.   : 2.119979  
##    Age 25-34            Age 35-44            Age 45-59         
##  Min.   :-1.4003816   Min.   :-1.5707223   Min.   :-1.2824562  
##  1st Qu.:-0.4302461   1st Qu.:-0.3254240   1st Qu.:-0.3592009  
##  Median :-0.0389146   Median : 0.0523434   Median : 0.0038675  
##  Mean   :-0.0005153   Mean   :-0.0004907   Mean   :-0.0001516  
##  3rd Qu.: 0.3109159   3rd Qu.: 0.3428460   3rd Qu.: 0.3320449  
##  Max.   : 2.4593123   Max.   : 1.3476436   Max.   : 2.0636600  
##    Age 60-74          Age 75 and Up       White Age 25-34   
##  Min.   :-1.5200978   Min.   :-2.813343   Min.   :-1.58588  
##  1st Qu.:-0.4931614   1st Qu.:-0.564325   1st Qu.:-0.57929  
##  Median : 0.1019088   Median : 0.028350   Median :-0.05022  
##  Mean   :-0.0005888   Mean   :-0.001022   Mean   :-0.00237  
##  3rd Qu.: 0.3763354   3rd Qu.: 0.592096   3rd Qu.: 0.45287  
##  Max.   : 2.0753534   Max.   : 2.572003   Max.   : 3.86079  
##  Receiving Public Assistance Households in Poverty Family Households   
##  Min.   :-2.880873           Min.   :-1.91846      Min.   :-1.7672010  
##  1st Qu.:-0.627072           1st Qu.:-0.43357      1st Qu.:-0.3123789  
##  Median : 0.131412           Median : 0.04745      Median :-0.0230496  
##  Mean   : 0.001978           Mean   : 0.00162      Mean   :-0.0000189  
##  3rd Qu.: 0.616547           3rd Qu.: 0.50650      3rd Qu.: 0.3305820  
##  Max.   : 2.454367           Max.   : 1.92720      Max.   : 1.7377624  
##  Same Sex Households Black Family Households Latinx/Hispanic Family Households
##  Min.   :-7.512903   Min.   :-4.686312       Min.   :-3.169116                
##  1st Qu.:-1.768855   1st Qu.:-0.544792       1st Qu.:-0.741370                
##  Median : 0.758340   Median :-0.041795       Median : 0.019176                
##  Mean   :-0.006823   Mean   : 0.003512       Mean   :-0.001147                
##  3rd Qu.: 0.801212   3rd Qu.: 0.701866       3rd Qu.: 0.642072                
##  Max.   : 6.085103   Max.   : 3.345314       Max.   : 4.893496                
##     Renters           Median Gross Rent<br>(Adjusted for Inflation)
##  Min.   :-2.1260688   Min.   :-101.59031                           
##  1st Qu.:-0.3769648   1st Qu.: -28.28939                           
##  Median :-0.0177048   Median :   1.91646                           
##  Mean   : 0.0005359   Mean   :   0.00003                           
##  3rd Qu.: 0.3867962   3rd Qu.:  24.16680                           
##  Max.   : 1.9589621   Max.   : 141.86682                           
##  Total Building Permits New Construction Permits  Renovation/Addition Permits
##  Min.   :-0.6561355     Min.   :-0.000000400594   Min.   :-4.435594          
##  1st Qu.:-0.0702990     1st Qu.:-0.000000105903   1st Qu.:-0.130151          
##  Median : 0.0377796     Median :-0.000000008706   Median : 0.028663          
##  Mean   :-0.0009406     Mean   : 0.000000014088   Mean   :-0.000972          
##  3rd Qu.: 0.0984252     3rd Qu.: 0.000000087743   3rd Qu.: 0.200696          
##  Max.   : 0.2482388     Max.   : 0.000000960679   Max.   : 0.732995          
##  Demolition Permits 
##  Min.   :-0.180760  
##  1st Qu.:-0.020362  
##  Median : 0.005779  
##  Mean   :-0.002708  
##  3rd Qu.: 0.028906  
##  Max.   : 0.072970

FIGURE 5

Philadelphia

##     Tract ID                SES          Total Population   
##  Min.   :42101000100   Min.   :-6922.6   Min.   :-422.7244  
##  1st Qu.:42101009550   1st Qu.:-1465.1   1st Qu.: -70.1728  
##  Median :42101019800   Median : -823.4   Median :  -3.6084  
##  Mean   :42101019734   Mean   :    0.0   Mean   :   0.0005  
##  3rd Qu.:42101030350   3rd Qu.:  222.7   3rd Qu.:  70.5926  
##  Max.   :42101039000   Max.   :27584.5   Max.   : 570.3958  
##                                          NA's   :2          
##  Total Housing Units  White (Non-Hispanic) Black (Non-Hispanic)
##  Min.   :-188.43816   Min.   :-4.170606    Min.   :-0.3815829  
##  1st Qu.: -11.22654   1st Qu.:-0.687730    1st Qu.:-0.0705096  
##  Median :  -3.44593   Median :-0.000448    Median : 0.0006008  
##  Mean   :  -0.00008   Mean   : 0.002489    Mean   : 0.0002281  
##  3rd Qu.:   9.59168   3rd Qu.: 0.780057    3rd Qu.: 0.0670383  
##  Max.   : 200.98247   Max.   : 2.827602    Max.   : 0.3901554  
##  NA's   :2            NA's   :2            NA's   :2           
##  Asian (Non-Hispanic) Latinx/Hispanic      Age Under 18      
##  Min.   :-5.37633     Min.   :-4.549495   Min.   :-2.415584  
##  1st Qu.:-0.98584     1st Qu.:-0.727887   1st Qu.:-0.412397  
##  Median :-0.02335     Median :-0.056979   Median :-0.011848  
##  Mean   : 0.01514     Mean   : 0.005673   Mean   : 0.002389  
##  3rd Qu.: 0.85691     3rd Qu.: 0.686588   3rd Qu.: 0.413309  
##  Max.   : 6.93635     Max.   : 4.752008   Max.   : 2.531215  
##  NA's   :2            NA's   :2           NA's   :2          
##    Age 18-24          Age 25-34           Age 35-44           Age 45-59        
##  Min.   :-4.11593   Min.   :-1.837413   Min.   :-2.378264   Min.   :-2.228414  
##  1st Qu.:-0.55610   1st Qu.:-0.460462   1st Qu.:-0.466346   1st Qu.:-0.352906  
##  Median : 0.10387   Median :-0.045891   Median :-0.024716   Median :-0.002642  
##  Mean   : 0.01062   Mean   : 0.002648   Mean   : 0.003885   Mean   : 0.001914  
##  3rd Qu.: 0.70755   3rd Qu.: 0.506268   3rd Qu.: 0.475350   3rd Qu.: 0.417917  
##  Max.   : 2.66764   Max.   : 2.158689   Max.   : 2.187867   Max.   : 1.505993  
##  NA's   :2          NA's   :2           NA's   :2           NA's   :2          
##    Age 60-74         Age 75 and Up        White Age 25-34    
##  Min.   :-1.897235   Min.   :-0.3408244   Min.   :-3.061913  
##  1st Qu.:-0.399080   1st Qu.:-0.0599441   1st Qu.:-0.772179  
##  Median : 0.004088   Median : 0.0002748   Median :-0.001728  
##  Mean   : 0.002111   Mean   : 0.0005957   Mean   : 0.011334  
##  3rd Qu.: 0.399470   3rd Qu.: 0.0667112   3rd Qu.: 0.689787  
##  Max.   : 1.617784   Max.   : 0.3186273   Max.   : 3.621127  
##  NA's   :2           NA's   :2            NA's   :2          
##  Receiving Public Assistance Households in Poverty Family Households   
##  Min.   :-2.610636           Min.   :-2.719736     Min.   :-2.1130134  
##  1st Qu.:-0.640410           1st Qu.:-0.601408     1st Qu.:-0.4665080  
##  Median : 0.040042           Median :-0.002575     Median : 0.0018835  
##  Mean   : 0.004203           Mean   : 0.007148     Mean   :-0.0004197  
##  3rd Qu.: 0.612010           3rd Qu.: 0.614683     3rd Qu.: 0.4583546  
##  Max.   : 2.956818           Max.   : 2.991261     Max.   : 2.7041664  
##  NA's   :2                   NA's   :2             NA's   :2           
##  Same Sex Households Black Family Households Latinx/Hispanic Family Households
##  Min.   :-16.08363   Min.   :-2.641102       Min.   :-6.08844                 
##  1st Qu.: -1.25252   1st Qu.:-0.598247       1st Qu.:-1.03514                 
##  Median :  0.56136   Median :-0.029140       Median :-0.06799                 
##  Mean   :  0.08961   Mean   : 0.002437       Mean   : 0.02289                 
##  3rd Qu.:  0.57801   3rd Qu.: 0.593434       3rd Qu.: 1.01164                 
##  Max.   : 10.60951   Max.   : 2.776316       Max.   : 6.25757                 
##  NA's   :2           NA's   :2               NA's   :2                        
##     Renters           Median Gross Rent<br>(Adjusted for Inflation)
##  Min.   :-0.1645688   Min.   :-117.68369                           
##  1st Qu.:-0.0430547   1st Qu.: -18.35425                           
##  Median :-0.0006880   Median :  -2.90927                           
##  Mean   : 0.0000127   Mean   :   0.00003                           
##  3rd Qu.: 0.0404612   3rd Qu.:  13.77636                           
##  Max.   : 0.2275484   Max.   : 195.43534                           
##  NA's   :2            NA's   :2                                    
##  Total Building Permits New Construction Permits Renovation/Addition Permits
##  Min.   :-3.692591      Min.   :-5.34583         Min.   :-2.566336          
##  1st Qu.:-0.637905      1st Qu.:-0.27138         1st Qu.:-0.457583          
##  Median : 0.011533      Median :-0.02858         Median : 0.038363          
##  Mean   : 0.003798      Mean   : 0.01970         Mean   : 0.002393          
##  3rd Qu.: 0.534005      3rd Qu.: 0.28236         3rd Qu.: 0.411527          
##  Max.   : 5.224498      Max.   : 6.67411         Max.   : 3.454235          
##                                                                             
##  Demolition Permits
##  Min.   :-3.19905  
##  1st Qu.:-0.78691  
##  Median :-0.19749  
##  Mean   : 0.03744  
##  3rd Qu.: 0.72894  
##  Max.   :10.01235  
##

Spatial Autoregressive Models

To keep with a strict definition of gentrification, as suggested by Ruth Glass’ original conceptualization, low-SES census tracts in 2014 were selected to determine how their change in SES over the five-year period correlated with other demographic, economic, and physical changes in the neighborhood. Figure 6 shows each city’s low-SES tracts in 2014 which were used as the primary sample in the analysis.

FIGURE 6

Boston

Philadelphia

For the spatial autoregressive (SAR) models, the change in SES served as the predictor (or X) for each individual neighborhood change indicator (or Y). Thus, a total of fifty-two SAR models were ran for the neighborhood change indicators of Boston and Philadelphia. Each SAR model incorporates a spatial lag of the dependent variable (or Y); for example, the change in one tract’s new construction building permits will affect the change in the neighboring tract’s new construction building permits. Direct, indirect, and total impact coefficients were computed for easier interpretation of the individual or direct impact the tract’s change in SES had on the change in the dependent variable, the indirect impact of the neighboring change in the dependent variable had on a tract’s change in the dependent variable, and the combined or total impact of both changes. Figures 7 and 8 detail the SAR results for both Boston and Philadelphia.

FIGURE 6

Boston

Variable Coefficient Rho…. LR.Test LM.Test Direct.Impact Indirect.Impact Total.Impact
Total Population 0.0037528 0.26559* 4.8158* 0.052933 0.003835197 0.0012336 0.005068844
Total Housing Units 0.0025361*** -0.047232 0.13475 0.0022278 0.002537717*** -0.0001125 0.002425223***
White (NH) 0.000073092*** 0.35834*** 9.2965** 0.3575 0.00007619783*** 0.0000365 0.0001126739***
Black (NH) 0.000013905 -0.016973 0.017483 7.304 1.39059E-05 -0.0000002 1.36798E-05
Asian (NH) -0.000087187** -0.087548 0.45028 0.28549 -0.00008737237** 0.0000070 -0.00008038142**
Latinx 0.000022106 0.043254 0.10473 2.1059 2.21178E-05 0.0000010 2.30752E-05
Age Under 18 -8.3531E-06 -0.34158** 7.6137** 0.1538 -8.62577E-06 0.0000023 -6.29076E-06
Age 18 to 24 -0.000007645 -0.0064414 0.0026711 0.57322 -7.64505E-06 0.0000000 -7.59751E-06
Age 25 to 34 0.000044607*** 0.20741 2.9707 1.174 0.00004518574*** 0.0000107 0.00005592594**
Age 35 to 44 0.000020256* 0.030262 0.061248 2.3467 0.00002026159* 0.0000006 2.08693E-05
Age 45 to 59 -0.000014452 -0.1724 1.5852 0.12549 -1.45706E-05 0.0000022 -1.23914E-05
Age 60 to 74 -0.000022935 0.0079479 0.0034458 2.1086 -2.29351E-05 -0.0000002 -2.31128E-05
Age 75 and Up -0.000022866 0.040325 0.10666 0.093415 -2.28763E-05 -0.0000009 -2.37975E-05
White 25 to 34 0.000073527*** 0.1477 1.45 0.35187 0.00007399819*** 0.0000119 0.0000858828***
Public Assistance -0.000035031 0.2777* 5.7378* 0.55861 -3.58776E-05 -0.0000122 -4.80907E-05
Households in Poverty -0.000028851* 0.1676 1.8361 2.3694 -0.00002909111* -0.0000054 -0.00003448376*
Family Households -0.000025409* 0.056965 0.27608 0.48233 -0.00002543236* -0.0000015 -0.00002689721*
Same Sex Households 0.000041895 0.025114 0.038286 0.048723 4.19025E-05 0.0000010 4.29416E-05
Black Family Households -0.000036414 -0.0097654 0.0062195 4.5204* -3.6415E-05 0.0000003 -3.60726E-05
Latinx Family Households -0.000037509 -0.05441 0.20302 1.4523 -3.75398E-05 0.0000019 -0.000035632
Renters -0.000044665*** -0.11135 0.59047 4.5918* -4.48176E-05 0.0000045 -4.0325E-05
Adjusted Median Gross Rent 0.00103251 0.14959 1.5062 0.14937 0.001039306 0.0001693 0.001208625
Total Building Permits 7.3691E-08 0.27944* 8.1588** 77.294*** 7.54966E-08 0.0000000 1.01403E-07
New Construction 0.000056082** 0.368*** 13.59*** 58.519*** 0.00005861343** 0.0000291 0.00008774837**
Renovation/Addition Building Permits 7.8196E-07 -0.0053388 0.0031759 33.046*** 7.81966E-07 0.0000000 7.77933E-07
Demolition Building Permits -0.0000023217*** 0.24076* 5.3077* 6.1462* -0.000002363015*** -0.0000007 -0.000003035605**

Boston (Z-Scored)

Variable Coefficient Rho…. LR.Test LM.Test Direct.Impact Indirect.Impact Total.Impact
Total Population 0.1680029 0.26597* 4.8326* 0.039484 0.1717034 0.05533062 0.2270341
Total Housing Units 0.53185851*** -0.051373 0.15858 0.0049421 0.5322491*** -0.02559092 0.5066581***
White (NH) 0.3779935*** 0.35436*** 9.0733** 0.53442 0.3936527*** 0.1855164* 0.5791691***
Black (NH) 0.06172601 -0.018611 0.021042 6.1525* 0.06173199 -0.001099586 0.0606324
Asian (NH) -0.2905413** -0.089325 0.46893 0.18619 -0.2911831** 0.0237443 -0.2674388**
Latinx -0.15220795 -0.050199 0.17282 0.49925 -0.1523147 0.007161771 -0.1451529
Age Under 18 -0.06171817 -0.34398** 7.7167** 0.24001 -0.06376207 0.01736137 -0.04640071
Age 18 to 24 -0.04492852 -0.0072792 0.0034119 0.15378 -0.04492918 0.000315508 -0.04461368
Age 25 to 34 0.325873*** 0.20975 3.0433 0.94081 0.3302056*** 0.07954314 0.4097487**
Age 35 to 44 0.193261* 0.03026 0.061242 2.3463 0.1933112* 0.005797808 0.199109
Age 45 to 59 -0.1318322 -0.17421 1.6215 0.23992 -0.1329342 0.02006879 -0.1128654
Age 60 to 74 -0.16749652 0.0089793 0.0044015 1.8164 -0.1675003 -0.001467834 -0.1689682
Age 75 and Up -0.1173785 0.040179 0.10589 0.08037 -0.1174322 -0.00471096 -0.1221432
White 25 to 34 0.3585641*** 0.14854 1.4664 0.30964 0.3608902*** 0.05833107 0.4192213***
Public Assistance -0.180016 0.27963* 5.808* 0.73526 -0.1844336 -0.06334089 -0.2477745
Households in Poverty -0.198686* 0.15818 1.6327 0.89555 -0.2001537* -0.03473479 -0.2348885*
Family Households -0.225704* 0.056754 0.27393 0.45502 -0.2259107* -0.01296155 -0.2388723*
Same Sex Households 0.0676749 0.024301 0.035839 0.0001562 0.06768614 0.001623132 0.06930927
Black Family Households -0.14775895 -0.010515 0.0072126 4.9798* -0.1477635 0.001495515 -0.146268
Latinx Family Households -0.15220795 -0.050199 0.17282 0.49925 -0.1523147 0.007161771 -0.1451529
Renters -0.3246701*** -0.11205 0.59731 4.4786* -0.325796*** 0.03284783 -0.2929482**
Adjusted Median Gross Rent 0.145939 0.14658 1.4385 0.009287 0.1468602 0.02338546 0.1702457
Total Building Permits -0.0054482 0.28067* 8.2036** 88.685*** -0.005583008 -0.001926604 -0.007509611
New Construction 0.2586042** 0.368*** 13.59*** 58.519*** 0.2702772** 0.1343465 0.4046238*
Renovation/Addition Building Permits 0.00695205 -0.0049671 0.00275 112.98*** 0.006952098 -3.33678E-05 0.00691873
Demolition Building Permits -0.3134277*** 0.23681* 5.1074* 5.4398* -0.3188125*** -0.08891964 -0.4077321**

Philadelphia

Variable Coefficient Rho…. LR.Test LM.Test Direct.Impact Indirect.Impact Total.Impact
Total Population 0.0116795 0.26651** 9.9237** 0.10196 0.01188515 0.003998826 0.01588398
Total Housing Units 0.00206617* 0.13662 2.3169 0.69458 0.002075121* 0.000314958 0.002390078*
White (NH) 0.000044608 0.50767*** 44.693*** 8.1734** 4.80644E-05 4.21146E-05 9.0179E-05
Black (NH) -8.3095E-06 0.26814** 9.6226** 1.6501 -8.45774E-06 -2.86808E-06 -1.13258E-05
Asian (NH) -0.000048264 0.18382* 3.8678* 0.081021 -4.86505E-05 -1.03824E-05 -5.90328E-05
Latinx 0.000066141 -0.013564 0.017415 0.5431 6.61433E-05 -8.79592E-07 6.52637E-05
Age Under 18 -0.00005422 0.2971*** 11.355*** 0.00049499 -5.54289E-05 -2.14968E-05 -7.69256E-05
Age 18 to 24 -0.000040789 0.019628 0.039861 0.28561 -4.07922E-05 -8.05567E-07 -4.15978E-05
Age 25 to 34 0.000090295** 0.038618 0.17898 0.86468 0.00009032544** 3.56338E-06 0.00009388882**
Age 35 to 44 0.000051928 0.055643 0.31789 0.14873 5.19645E-05 2.99521E-06 5.49597E-05
Age 45 to 59 -0.000054179* 0.098333 1.064 0.26357 -0.00005429885* -5.73416E-06 -0.00006003302*
Age 60 to 74 -0.000035801 0.15154 2.628 0.55181 -3.59929E-05 -6.14312E-06 -4.21361E-05
Age 75 and Up 2.9741E-06 0.20174* 4.1623* 1.3515 3.00306E-06 7.15704E-07 3.71876E-06
White 25 to 34 0.000142089** 0.20008* 5.1543* 10.908*** 0.0001434488** 3.38521E-05 0.0001773009**
Public Assistance -0.000112922** 0.073985 0.64915 0.033839 -0.0001130624** -8.7985E-06 -0.0001218609**
Households in Poverty -0.000154205*** -0.098659 0.97388 0.52426 -0.0001545298*** 1.40438E-05 -0.000140486***
Family Households -2.4133E-06 0.28781*** 10.519** 1.798 -2.4635E-06 -9.16052E-07 -3.37955E-06
Same Sex Households -0.00027354 -0.0025438 0.0006577 0.19345 -0.000273544 6.8804E-07 -0.000272856
Black Family Households -0.000054515 0.31028*** 15.025*** 19.547*** -5.58516E-05 -2.29603E-05 -7.88119E-05
Latinx Family Households 0.000123878 -0.073182 0.50421 0.00012195 0.000124022 -8.51336E-06 0.000115509
Renters -0.0000104448*** 0.10589 1.4084 3.9702* -0.00001047165*** -1.1987E-06 -0.00001167035***
Adjusted Median Gross Rent 0.0044434*** -0.028598 0.089446 0.076354 0.004444204*** -0.000123195 0.004321009***
Total Building Permits -0.000120687*** 0.48146*** 38.078*** 0.47629 -0.000128874*** -0.0001028305* -0.0002317045**
New Construction -0.000014226 0.47627*** 34.272*** 1.9958 -1.51653E-05 -1.18772E-05 -2.70425E-05
Renovation/Addition Building Permits -0.000066524* 0.372*** 19.985*** 1.03 -0.00006897363* -3.65918E-05 -0.0001055654*
Demolition Building Permits -0.000138982** 0.62293*** 83.766*** 1.8766 -0.0001577073** -0.0002087515** -0.0003664588**

Philadelphia (Z-Scored)

Variable Coefficient Rho…. LR.Test LM.Test Direct.Impact Indirect.Impact Total.Impact
Total Population 0.1223822 0.26712** 9.9716** 0.13412 0.1245476 0.04202844 0.166576
Total Housing Units 0.1711895* 0.1355 2.2785 0.85675 0.1719187** 0.02585328 0.197772**
White (NH) 0.0579562 0.50887*** 44.894*** 8.6492** 0.06247406 0.05497593 0.11745
Black (NH) -0.1153198 0.26912** 9.6844** 1.9256 -0.1173932 -0.03999536 -0.1573886
Asian (NH) -0.040471 0.1832* 3.8404 0.12834 -0.04079261 -0.008671091 -0.0494637
Latinx 0.08356909 -0.013568 0.017425 0.54963 0.08357248 -0.0011117 0.08246078
Age Under 18 -0.1124059 0.29666*** 11.318*** 0.0024885 -0.1149037 -0.04447565 -0.1593794
Age 18 to 24 -0.0612834 0.017646 0.03222 0.017006 -0.0612876 -0.001086398 -0.06237399
Age 25 to 34 0.19637909** 0.038599 0.1788 0.86322 0.1964446** 0.007745925 0.2041905**
Age 35 to 44 0.1080844 0.055384 0.31494 0.17162 0.108159 0.006203834 0.1143628
Age 45 to 59 -0.1365705* 0.0989 1.0766 0.31716 -0.1368759* -0.01454508 -0.1514209*
Age 60 to 74 -0.0866759 0.15077 2.6009 0.6806 -0.08713605 -0.01478554 -0.1019216
Age 75 and Up 0.0460101 0.20276* 4.206* 1.1432 0.04646287 0.01114069 0.05760356
White 25 to 34 0.18131** 0.20003* 5.1491* 10.939*** 0.1830445** 0.04318223 0.2262267**
Public Assistance -0.192269** 0.073984 0.64909 0.03399 -0.1925069** -0.01498074 -0.2074876**
Households in Poverty -0.2352527*** -0.09782 0.95786 0.45903 -0.2357393*** 0.02125439 -0.2144849***
Family Households -0.0039519 0.28963*** 10.655** 2.2441 -0.004035237 -0.00151299 -0.005548227
Same Sex Households -0.118740213 -0.000198 3.9861E-06 0.028256 -0.1187402 2.32895E-05 -0.1187169
Black Family Households -0.0941155 0.31335*** 15.321*** 22.802*** -0.09647416 -0.04019383 -0.136668
Latinx Family Households 0.0978848 -0.073325 0.50613 0.00075825 0.09799911 -0.006739444 0.09125966
Renters -0.23069459*** 0.10619 1.4168 4.0265* -0.231291*** -0.02655715 -0.2578481***
Adjusted Median Gross Rent 0.222371638*** -0.026081 0.074456 0.01052 0.2224049*** -0.005633178 0.2167717**
Total Building Permits -0.214975*** 0.47958*** 37.645*** 0.30626 -0.2294179*** -0.181824** -0.4112419***
New Construction -0.02326 0.4787*** 34.565*** 2.2683 -0.02481547 -0.01960596 -0.04442143
Renovation/Addition Building Permits -0.15683552* 0.36928*** 19.644*** 0.72569 -0.1625143** -0.08529631* -0.2478106*
Demolition Building Permits -0.1747322*** 0.62189*** 83.345*** 1.6303 -0.1981605*** -0.261304** -0.4594645**

Initial Findings

Using the testable operationalization of gentrification—reflecting Ruth Glass’ original conceptualization—where originally low-SES neighborhoods see a positive change in their SES, some common characteristics occurred within Boston and Philadelphia. These characteristics align with previous findings and commonly held notions of gentrification: it correlates with an increase in housing units, younger Non-Hispanic White populations (age 25-to-34 years-old), and a decrease (or possible displacement) of low-income or impoverished populations. Gentrification in both cities also correlated with a decrease in renter populations and a decrease in building demolition speculation – phenomena seldom discussed in gentrification research.

Gentrification also manifested in unique ways in both cities. For Boston, the rise in SES for originally low-SES census tracts correlated with an increase in the Non-Hispanic White population and a decrease in Asian populations. Gentrification, however, did not correlate with any changes in the race or ethnicity of the residential populations in Philadelphia (except for the previously mentioned positive relationship with an increase in Non-Hispanic Whites aged between 25-to-34-years-old). In Boston, gentrification also had a positive relationship with the concentration of 35-to-44-year-olds while, in Philadelphia, it had a negative relationship with the concentration of 45-to-59-year-olds.

Gentrification correlated negatively with the concentration of Philadelphians receiving some form of public assistance while having no relationship in Boston – even though gentrification in both cities correlated with a decrease in households living in poverty. In Boston, it also saw a negative relationship with family households or housing situations with where the residents are related – but not in Philadelphia.

Gentrification also manifested differently for building speculation and activity. In Boston, it correlated with an increase in new construction building permits while in Philadelphia it correlated negatively with renovation or addition building permits.