1. Demographic Multipliers: Recent National and State Findings
Prepared By DAVID LISTOKIN, Ph.D.
ROBERT W. BURCHELL, Ph.D.
Prepared For NATIONAL IMPACT FEE ROUND TABLE (NIFR) NATIONAL CONFERENCE
ARLINGTON, VIRGINIA
OCTOBER 2006

2. PRESENTATION OVERVIEW
Perspective on Demographic Multipliers: definition, application, and literature
Changes in Multipliers Over Time
Results of New National Data
Results of New State Data (New Jersey example)
Conclusions

3. DEFINITIONS OF DEMOGRAPHIC MULTIPLIERS
Demographic multipliers – the number and profile of the populations associated with new residential and nonresidential development
Residential multipliers – Resident population associated with housing
Nonresidential multipliers – Worker population associated with commercial and other business uses

4. USE OF DEMOGRAPHIC MULTIPLIERS
Interlinked Applications
Impact fees
Fiscal impact analysis
School enrollment projections
Public staffing analysis
Market studies
Calculating development standards
“Cost of sprawl” studies
Other applications

5. DEMOGRAPHIC MULTIPLIERS LITERATURE OVERVIEW (EXAMPLES)
The Fiscal Impact Handbook (1978)
The Practitioner’s Guide to Fiscal Impact Analysis (1985)
Development Impact Assessment Handbook and Model (1994)
Planner’s Estimating Guide (2004)
Residential Demographic Multipliers (2006)
Fiscal and Impact Fee Studies (1970s-2000s)
Other
Conclusion: Extensive literature—but of varying quality and dating is often an issue

6. U.S. RESIDENTIAL DEMOGRAPHIC MULTIPLIERS OVER TIME
1970
1990
2000 
(Change)
Single-Family (4BR)
Household Size
4.67
3.70
3.53
-24%
School children
1.92
1.18
1.01
-47%
Town House (3BR)
4.07
2.69
2.55
-37%
1.33
0.53
0.44
-67%
Garden Apartment (2 BR)
2.56
2.22
2.19
-14%
0.27
0.34
0.29
+0.7%
Conclusion: There are generally significant decreases over time in household size and school children in most standard housing types. Current data is therefore essential.

7. Author: Center for Urban Policy Research, Rutgers University
FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS STUDY
Author: Center for Urban Policy Research, Rutgers University
Data: 2000 PUMS, U.S. Housing Constructed
Geography: All U.S., 50 States, and District of Columbia
Release: Mid-2006 and available from FMF DataPlace™ (

8. Household size (HS) – Total persons per housing unit
FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: DATA FIELDS (I)
Multipliers comprise
Household size (HS) – Total persons per housing unit
Age distribution of household members – 0-4, 5-13, 14-17, 18-24, 25-44, 45-64, 65-74, 75+
Total school-age children (SAC)
Total public school-age children (PSAC)
SAC who attend public school
SAC and PSAC by grade group – (K-2, 3-6, 7-9, 10-12, 9)

9. FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: DATA FIELDS (II)
Multipliers Differentiated by:
Housing Type
Single-family detached
Single-family attached
2-4 Unit
5+ Unit
Mobile home
Housing Size
1-5 bedrooms
Housing Price (updated to 2005)
All values
Terciles (thirds): 1st – 33rd percentile, 34th – 66th percentile, 67th – 100 percentile
Housing Tenure
Ownership or rental

10. FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (I)
Housing Type, Size, and Value
U.S. Average
Household Size (HS)
Public School-Age Children (PSAC)
Single-Family Detached, 3 BR
All Values
2.84
0.51
1st-33rd percentile
3.01
0.69
34th-66th percentile
2.82
0.49
67th-100th percentile
2.73
0.40
Single-Family Detached, 4 BR
3.53
0.85
3.77
1.07
3.51
0.83
3.35

11. FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (II)
Housing Type, Size, Value, and Tenure
U.S. Average
Household Size (HS)
Public School-Age Children (PSAC)
5+ Units Own, 2 Bedrooms
All Values
1.70
0.07
1st-33rd percentile
1.74
0.11
34th-66th percentile
1.68
0.06
67th-100th percentile
0.04
5+ Units Rent, 2 Bedrooms
2.19
0.27
2.25
0.34
2.23
2.10
0.18
Conclusion: Variations in demographics associated with housing type, housing size, housing value, and housing tenure.

12. FANNIE MAE FOUNDATION (FMF) – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (III)
Housing Type and Size
U.S. Average
Household Size (HS)
Age distribution
Single-family Detached, 4BR
3.53
Single-family Attached, 2BR
1.93
Conclusion: Need to pay more attention to the age distribution of household members

13. NJ OFFICE OF SMART OF GROWTH (OSG) – RUTGERS DEMOGRAPHIC MULTIPLIERS STUDY
Author: Center for Urban Policy Research, Rutgers University
Data: 2000 PUMS, NJ Housing Constructed , Field studies and other
Geography: NJ, All State and 3 regions
Multiplier fields:
HS, SAC and PSAC by housing type, size, value, tenure, and state region
Statistics:
Regression analysis of characteristics associated with variation in multipliers
Multipliers presented with sample size, standard error, and confidence interval
Other: affordable housing, transit oriented development (TOD), and nonresidential multipliers

14. Public School-Age Children (PSAC)
OSG – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (I)
Housing Type, Size, and Value
NJ Average
Household Size (HS)
Public School-Age Children (PSAC)
Single-Family Detached,
3 Bedroom
All Values
2.977
0.484
Below median
3.038
0.542
Above median
2.913
0.423
Single-Family Attached,
2.655
0.381
2.823
0.491
2.444
0.244
Conclusion: Variation in demographics associated with housing type, housing size, and housing value (housing tenure and region)

15. OSG – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (II)
NJ Average
90% Confidence Interval
Housing Type, Size, and Value
Public School-Age Children (PSAC)
Low
high
Single-Family Attached,
2 Bedroom
All Values
0.126
0.102
0.151
Below median
0.164
0.203
Above median
0.081
0.052
0.110
3 Bedroom
0.381
0.336
0.427
0.491
0.420
0.562
0.244
0.191
0.296
Conclusion: Variations around multiplier averages warrant heightened attention

16. Conclusion: What are appropriate multipliers for affordable housing?
OSG – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (III)
A. PUMS--Household Size and Public School-Age Children
For Low- and Moderate-Income Households (LMI) in New Jersey (2000)
Household Size (HS)
Public School-Age Children (PSAC)
All Housing Types and Bedrooms
2.35
0.45
Single-Family Attached
2 Bedroom
2.09
0.32
3 Bedroom
3.05
0.78
5+ Units, Rent
2.76
0.62
3.82
1.27
B. Case Study Investigation – Average PSAC for affordable housing units of 0.52—but range of 0.22 to 1.42
Conclusion: What are appropriate multipliers for affordable housing?

17. Transit Oriented Development (TOD)
OSG – RUTGERS RESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED FINDINGS (IV)
Transit Oriented Development (TOD)
Field investigation of 10 TODs with 2,200 housing units found they contained 50 public school-age children (PSAC)—or a PSAC multiplier of 0.02 per housing unit
Application of standard residential multipliers (average 0.14 PSAC per unit) would have projected about 300 PSAC
Conclusion: What are appropriate multipliers for emerging housing types such as TODs?

18. Conclusion: Need better data on nonresidential multipliers
OSG – RUTGERS NONRESIDENTIAL DEMOGRAPHIC MULTIPLIERS: SELECTED EXAMPLES (V)
Variation in nonresidential multipliers – retail example
Employees per 1,000 ft.2
State of Washington (1998)
CBECS (2001)
CA Dept. Energy (1996)
ITE Trip Generation (1997)
Census of Retail (1997)
Conclusion: Need better data on nonresidential multipliers

19. DEMOGRAPHIC MULTIPLIERS CONCLUSION
Critical data with many applications
“Moving target” – changing figures over time
Variations in residential demographic multipliers have been associated with such characteristics as housing type, housing size, housing value, and housing tenure
Emerging areas of inquiry:
Statistical analysis
Household age distribution
Emerging residential development categories
Nonresidential multipliers