In the 1970s and 1980s, researchers at Rutgers University (at an academic unit that ultimately became a component of the Rutgers Edward J. Bloustein School of Planning and Public Policy) published a series of national studies(hereinafter, the “Rutgers–Bloustein studies”) that contained information on residential demographic multipliers—the number and profile of people(including school-age and public school children) found in different categories of housing units.

The Rutgers–Bloustein studies provided demographic information for the nation, and for each of the census regions(e.g., Northeast United States) and census subregions (e.g., Middle Atlantic States, which includes New Jersey).The Rutgers–Bloustein studies were widely applied throughout the United States as well as in New Jersey. In 2006, a New Jersey-specific multiplier study was conducted by Rutgers–Bloustein that examined housing built in the Garden State between 1990 and 2000. Inevitably, however, the Rutgers–Bloustein studies became dated over time and do not reflect the demographic reality of a general decline over time in the average household size and the average number of pupils per housing unit. For instance, the number of public school children in the average Newer Built New Jersey 4-bedroom single-family detached (SFD) home dropped from1.21 in 1980 (units built 1970 to 1980) to 0.85 in 2016 (units built 2000 to2016), a decline of about 30 percent. In other words, the introduction of100 4-bedroom SFDs in New Jersey as of 2016 would generate only about85 public school children as compared to 121 pupils a few decades earlier.

In short, the practice of using the older published demographic studies produces an erroneous overstatement of the population generated by new development in New Jersey. To improve the state of our knowledge, this Rutgers–Bloustein study produces demographic information on household size and pupil generation (both school-age and public school specific) that is both current (uses the latest released American Community Survey [ACS] data from the U.S. Census Bureau) and New Jersey–specific (contains demographic data unique to this state alone). Our study taps the 2012–2016 American Community Survey for New Jersey—the latest ACS release as of the writing of this report and a primary arms-length source used by demographers, urban planners, and other researchers.

The document’s data are invaluable for accurate demographic projections and development impact assessment. Yet, as with any data, there are limitations, and we later discuss shortcomings of the information in the current investigation. More broadly, sensitivity is required whenever projecting the population of new development from any given demographic multipliers, for it is inherently difficult to “crystal ball” the exact demographic future and impact. Further, it is important that the study’s data not be misused to exclude certain categories of housing, such as homes with more bedrooms, or rental housing, or affordable housing, or for that matter housing in general, because of the apprehension that residential development will generate “too many” new residents and public schoolchildren. That exclusionary perspective does not acknowledge current data(the demographic multipliers have generally declined in size over time),subverts good planning (smart growth calls for a range of housing and a mix of land uses), and violates the Mount Laurel principle of all communities in New Jersey having the obligation of meeting the spectrum of the state’s housing needs.