No. 40
December 13, 1999
Steven Hayward*

The summary of the new 1997 National Resources Inventory (NRI) is just out from the U.S. Department of Agriculture. It concludes that the rate of land being urbanized in the U.S. has increased rapidly in the 1990s, to more than three million acres a year, and is providing fresh fuel for those who see urban sprawl as a crisis requiring significant new land regulation. The NRI reports some jaw-dropping statistics, such as the finding that Pennsylvania has urbanized the second largest amount of land of all the 50 states, just behind fast-growing Texas and just ahead of fast-growing Georgia. (See Table 1.) These numbers seem incredible and alarming for a slow-growing state such as Pennsylvania, which is perhaps why we should question their accuracy.

So far, the only part of the NRI that has been released is the summary. Until the detailed state-by-state data are released, it will be impossible to do a thorough analysis. A number of observations and anomalies can be noted from the summary, however.

First, the NRI itself cautions that "Statistics derived from the NRI database are estimates and not absolutes. This means that there is some amount of uncertainty in any result obtained using NRI data." (p. 4, emphasis added.) How much uncertainty?

The 1997 NRI does not explain this revision, but it has the effect of swelling the land-developed figure for the 1992-1997 period. (The 1992 NRI, it should be noted, has been deleted from the Department of Agriculture website.) If the 1992 NRI was off by more than 200,000 acres for Pennsylvania, what reason do we have to be more confident of the current findings? There is ample precedent of error for these land development statistics. In 1981, the Soil Conservation Service (SCS) estimated that three million acres a year were being developed (the same rate as is now reported), but they had to correct that estimate by 1984 when the persistent inquiries of various scholars concluded that the SCS had overestimated development by a factor of three.

Second, it should be borne in mind that ascertaining the amount of developed land is a secondary purpose of the NRI; hence, Vice President Gore’s use of the NRI data represents another case of blatant politicization of the bureaucracy. The NRI’s primary purpose is to determine the amount and condition of various rural land resource categories, especially farmland. Most of its nearly 800,000 "sample points" are in farming and rural areas. The discrepancies and anomalies in the summary data suggest that a great deal more needs to be known before the findings of the 1997 NRI for developed land can be taken at face value. The plot thickens in Table 2 below.

At the end of the day, growth and sprawl must bear some relation to population growth. Table 2 compares population growth and land developed from 1992-1997, and computes a simple ratio of land developed for every new person. If the NRI figures are to be believed, they suggest that California is developing its land quite efficiently. By these numbers, California is developing much more efficiently than Texas, Georgia, Arizona, and even "smart growth" Maryland. Most startling of all, California used less land per person than Oregon! And the finding that there were 28 acres of development for each additional person in Pennsylvania is strikingly out of whack even with other slow-growing states of the northeast. A cross-check of building permits and commercial square footage in Pennsylvania will probably reveal that, for the NRI estimate to be correct, each new house would have to have been 45,000 square feet, and each new Wal-Mart the size of the Astrodome.

Nevada and Arizona present an especially striking anomaly. Sprawl critics have been claiming that Las Vegas is being developed at a rate of two acres an hour, yet the NRI reports a land use rate for the whole state of Nevada less than half of that total. Nevada’s population growth was nearly twice the population growth of neighboring—and fast-growing—Arizona, yet Arizona is reported to have developed four times as much land. Someone is wrong here. We suspect the Nevada number is wildly inaccurate, in what should be an easy state to make accurate estimates, since development is overwhelmingly confined to two metropolitan areas (Las Vegas and Reno). If the Nevada estimate is so far wrong, it casts large doubts about the estimates for other states. The lesson for legislators is clear.

Government statistics on sprawl are politicized, exaggerated, and ultimately unreliable. Their intention, it seems clear, is to create a crisis where none exists. The policy debate on this issue must be based on facts and reality, not estimates and speculations.

* Dr. Steven Hayward is director of the Center for Environmental and Regulatory Reform at the California-based Pacific Research Institute.