Four out of 10 households in Marion County are occupied by someone who is 65 or older.

That is perhaps no surprise in Florida which, according to recently released census statistics, ranks first in the nation for percentage of older households.

E-mail (Print on demand only)

This Florida Population Studies series bulletin features current estimates of the number of households and average household size for each county and state. Comparative data to both the 2000 and 1990 censuses are included along with a discussion of the estimation methodology used.

Note: This publication is included with a Florida Population Studies annual subscription ($40).

The housing unit (HU) method is often characterized as inferior to other methods for estimating the population of states and local areas. We believe this characterization must be challenged. In this article we evaluate population estimates produced by the housing unit method and by three other commonly used methods: component 11, ratio correlation, and administrative records.

Many different techniques can be used for making population projections. Most fall into four general categories: trend extrapolation, ratio extrapolation, cohort-component and structural. Techniques within these categories differ considerably in terms of their complexity and sophistication. A common perception among producers (and users) of population projections is that complex and/or sophisticated techniques produce more accurate forecasts than simple and/or naive techniques.

The housing unit method of population estimation is often characterized as being imprecise and having upward bias. In an earlier paper we argued that the method itself cannot be properly characterized by a particular level of precision or direction of bias. Only specific techniques of applying the method can have such characteristics. In that paper we presented several new techniques for estimating the number of households and average number of persons per household (PPH).

In the housing unit method, population is calculated as the number of households times the average number of persons per household (PPH), plus the population residing in group quarters facilities. Estimates of households and the group quarters population can be derived directly from concurrent data series, but estimates of PPH have traditionally been based on previous values or estimates for larger areas. In our study, we developed several regression models in which PPH estimates were based on symptomatic indicators of PPH change.

The housing unit method is the most commonly used method for making small-area population estimates in the United States and is widely used in other countries as well. These estimates are used for a variety of budgeting, planning, and analytical purposes in both the public and private sectors; consequently, detailed evaluations of their accuracy are essential. In this study, we evaluate the precision and bias of April 1, 2000 population estimates for counties and subcounty areas in Florida.

Annual subscription (3 publications). E-mail or Print.

The Florida Population Studies series is comprised of three bulletin-type publications produced each year:

• 1) Estimates of the number of households and average household size;
• 2) Projections of Florida county population (high, medium and low); and
• 3) Population estimates and projections by age, sex, race, and Hispanic origin for Florida and its counties (this bulletin is also available on CD-ROM).