Your local future

American Demographics, April, 1996 by Brad Edmondson

How fast will your market grow? It's easy to get an answer. Several private data companies will provide reliable population figures and demographics for any local area projected five years or further into the future. The cost: $100 or less.

But maybe you don't have $100. And even if you do, it's always a good idea to look at a second set of projections before you make a business decision. After all, population projections are just current estimates combined with a formula that incorporates the author's assumptions about births, deaths, and migration. If two authors have different assumptions, their numbers will be different.

Let's say that you want to open a branch office in Washoe County, Nevada, also known as Reno. The population of that metropolitan area could increase from 282,340 in 1994 to 319,970 in 2000, according to NPA Data Services of Washington, D.C. But a lot of Reno's future will depend on the extent of migration from California. Reno could grow at a snail's pace, from 278,350 in 1994 to only 280,690 in 2000, according to the Nevada State Data Center, if a booming California encourages more Golden State residents to stay. Reno could grow faster (to 317,850) if California does moderately well, or it could really take off (to 337,210) if California's economy does poorly.

State data centers often produce the highest-quality local projections because they are most familiar with the quirks of local markets. Each state has a data center, and most states make their own county-level projections. The accompanying chart shows the phone number of each state's data center; the date of the most recently published projections and the next publication date, if scheduled; a brief description of the electronic and print formats available; whether the projections are available by age, sex, and race; and whether they are published for counties, cities, and townships.

When you call a state, keep these four questions in mind.

1) What's the baseline? Most state projections are based on the 1990 census, but there are still a few laggards. Pennsylvania has not produced any new numbers since 1988, for example, and New York's new projections are still unpublished. Also, keep in mind that some states use noncensus numbers as a baseline. Texas uses more recent immigration numbers than the bureau uses. California bases its projections on its own survey. This isn't necessarily bad, but it does have a big effect on the results.

2) What's the method? Most population projections use the "cohort-component" method, which breaks an area's population into age groups, or birth cohorts, and then applies assumptions about how the components of demographic change--births, deaths, and migration--will affect each group. But Hawaii, New Jersey, Utah, and a few other states modify their cohort-component assumptions with an economic model that takes into account the effects of changes in employment, wages, and personal income. Adding in these factors could sharpen the results for states that attract a lot of migrants.

3) What are the assumptions? Nevada isn't the only state that factors in the effects of specific events on local populations. Minnesota, for example, adjusts its county-level numbers whenever a college campus closes or an employer announces major layoffs. And Maryland assumes that its citizens will have lower fertility than census numbers would imply.

4) What else is going on? Budget cuts and other pressures can throw a state data center into chaos or even put it out of business. Alaska's data center was all but eliminated in 1994, and Mississippi did not return repeated phone calls. So even if our listing says that something is not available, it may still be worthwhile to call and ask. There may be a demographer lurking out there whose work could help you.

5) What else is there? State data centers are supported by a network of about 1,800 local agencies, some of which produce their own estimates and projections for specific markets. An appendix to the annual Census Catalog & Guide contains the names and phone numbers of these affiliates. It is available at most public libraries, or for $19 from the Government Printing Office at (202) 512-1800; ask for stock number 003-024-08782-1. Up-to-date phone numbers and contact names for the 50 main branches of the state data centers are also maintained on the Census Bureau's site on the World Wide Web (http:/www.census.gov). And the Census Bureau's public information office can refer you to a local affiliate; call (301) 457-3030.

--Research assistance provided by

Stephanie Meltzer and Berna Miller