Population Change in The Delaware Valley, 1930-2000	No. 82 April 2006

The Delaware Valley Regional Planning Commission is an interstate, intercounty and intercity agency that provides comprehensive and coordinated planning for the orderly growth of the Greater Philadelphia region. As the region's metropolitan planning organization (MPO), the Commission provides technical assistance and services to its member state, county, and local governments, the private sector, and the public. Delaware Valley Data is our periodic series of free data bulletins and analytical reports. This data bulletin documents municipal, county, and regional population trends between 1930 and 2000 for the nine-county DVRPC region, which includes Bucks, Chester, Delaware, Montgomery, and Philadelphia counties in Pennsylvania and Burlington, Camden, Gloucester, and Mercer counties in New Jersey.

Table 1 provides county and regional population data for each decade between 1930 and 2000, and Table 2 describes the percent and absolute changes in population between 1930 and 1970 and again between 1970 and 2000. Between 1930 and 2000, the nine-county DVRPC region gained almost 2.1 million new residents, including over 1.1 million in the five Pennsylvania counties and over 900,000 residents in the region's New Jersey counties. Most of this growth took place between 1930 and 1970, with the region's population increasing by over 50% between 1930 and 1970 but by only 5% between 1970 and 2000.

Figure 1 compares the percent change in population between 1930 and 1970 with changes between 1970 and 2000. Between 1930 and 1970, the population of each of the eight suburban counties, while the City of Philadelphia's population peaked in 1950 before declining to its earlier 1930 level by 1970. The largest percentage increases during these early decades occurred in Bucks and Burlington Counties.

In comparison, the decades between 1970 and 2000 can be characterized more as a period of population shift, rather than growth. Between 1970 and 2000, the region's overall population grew by only 5%, as both the City of Philadelphia and Delaware County, home to many of the region's older first suburbs, saw their population decline. Additionally, the remaining seven suburban counties realized more moderate population increases (in terms of percentage) than had been seen in earlier decades.

Figure 2 illustrates the absolute change in population between 1930 and 1970 and between 1970 and 2000. The nine-county region gained over 1.8 million residents between 1930 and 1970. The population of the City of Philadelphia in 1970 was almost identical to the City's population in 1930. Every suburban county realized growth, with the greatest absolute increases seen in Montgomery, Delaware, and Bucks counties in Pennsylvania.

Almost two-thirds of the region's absolute population increase between 1930 and 1970 occurred in the four suburban Pennsylvania counties, with Montgomery, Bucks, and Delaware counties each gaining comparable numbers of new residents. About 37% of the region's growth was realized in New Jersey during this time period, with Burlington and Camden counties gaining the most residents.

Between 1970 and 2000, however, the region gained less than 260,000 people overall, despite significant increases in certain suburban municipalities. While much of this reduction was due to the loss of over 430,000 residents in the City of Philadelphia and an additional 50,000 people in Delaware County, the region's suburban counties also experienced much more moderate increases than in earlier decades. The exception is Chester County, which gained almost the same number of residents between 1930 and 1970 as between 1970 and 2000.

Losses of population in both Philadelphia and Delaware County during these most recent decades counterbalanced gains in the other three suburban Pennsylvania counties, resulting in a net population loss in Southeastern Pennsylvania. Region-wide, Bucks, Chester, Montgomery and Burlington counties gained the most new residents, while Camden and Mercer County, home to the cities of Camden and Trenton, continued to gain residents but at a more moderate pace than the region's other suburban counties.

These shifts in population from Philadelphia and the region's other cities and older communities to the suburbs have resulted in differences in the share of the region's residents living in each county over the decades. Figure 3 compares the proportionate share of the region's population living in each of the nine counties in 1930, 1970, and 2000. The share of the region's residents living in Philadelphia has progressively declined, while the percentage living in the Pennsylvania and New Jersey suburbs has simultaneously increased.

Appendix A provides municipal-level population statistics, and Maps 1 and 2 illustrate absolute and percent population change between 1930 and 2000, by municipality. Table 3 identifies the region's fifteen fastest growing municipalities between 1930 and 2000.

Map 1
Map 2
Appendix A [.xls | .pdf]