1 Greg Harper Population Division September 28, 2006 Presented to FSCPE Fall Meeting Reviewing Subcounty Population Estimates

2 Overview Subcounty population estimates methodology Review of housing unit data Review of subcounty population estimates

Subcounty Population Estimates Methodology Distributive Housing Unit Method Change in housing units since the last Census at the subcounty level is used to distribute the estimated county population Components of Housing Unit Change Residential Construction Mobile Home Placements Housing Unit Loss

4 Housing Unit Estimates Equation HU 06 = HU 00 + (NC 06 + NM 06 ) – HL 06 HU 06 = Estimated 2006 Housing Units HU 00 = 2000 Housing Unit Estimates Base NC 06 = Estimated New Residential Construction: NM 06 = Estimated New Residential Mobile Homes: HL 06 = Estimated Residential Housing Loss:

5 Estimated Residential Construction Building Permits –Compiled by the Census Bureau’s manufacturing and Construction Division (MCD) Nonpermitted Construction –Estimated from annual Survey of Construction

6 Mobile Home Placements State mobile shipments data distributed to subcounty areas based on the subcounty area’s share of mobile homes in Census 2000 Sample data retabulated for consistency with 100 percent housing unit data

7 Housing Unit Loss Housing Unit Loss Data derived from 1997–2003 AHS National Sample Type of Non-interview Considered a Loss –Type B, 16 - Interior exposed to the elements –Type C, 30 – Demolished or disaster loss –Type C, 31 – House or mobile home moved Categories for Developing Loss Rates –Mobile Homes –Age of Structure (seven categories)

8 Summary of Loss Rates 0.295% Total Annual Loss Rate Mobile Homes: 1.580% Houses or Apartments – : 0.058% – : 0.092% – : 0.100% – : 0.178% – : 0.224% – : 0.359% –Pre-1940: 0.395%

9 Uncontrolled Subcounty Population Estimate UHHP 06 = HU 06 * OCC 00 * PPH 00 UHHP 06 = Uncontrolled 2002 subcounty household population estimate HU 06 = 2006 Housing Unit Estimate OCC 00 = Census 2000 occupancy rate PPH 00 = Census 2000 population per household

10 Final Subcounty Population Estimate SCPOP 06 = [UHHP 06 * (ARCHHP 06 /HUMHHP 06 )] + GQ 06 SCPOP 06 = Final 2006 subcounty population estimate UHHP 06 = Uncontrolled 2006 household population estimate ARCHHP 06 = 2006 Administrative Records method county household population estimate HUMHHP 06 = 2006 Housing Unit method county household population6 estimate ARCHHP 06 /HUMHHP 06 = Rake Factor GQ 06 = 2006 group quarters population estimate

11 The Housing Unit Review File File contains components of housing unit change Available in late October Two months of review Can be made available to local governments Data for areas affected by Katrina

12 Housing Unit Review File Components PER7_2005 = building permits issued in calendar year 2004 *.98 –Assumes six-month lag time between permit issuance and completed construction –Assumes 2 percent of permits do not result in completed construction

13 Housing Unit Review File Components MOB7_2005 = New mobile homes allocated to place from July 1, 2004 to July 1, 2005 NPHB7_2005 = Nonpermitted residential construction allocated to place from July 1, 2004 to July 1, 2005 –If permits are issued for locality, NPHB will be 0

14 Housing Unit Review File Components NPHD7_2005 = Estimated housing unit loss from July 1, 2004 to July 1, 2005 –The same loss rate is applied to updated estimates of housing units so the amount of loss will not change much from year to year HSG7_2005 = 2005 estimate of housing units HSG7_2005 = HSG7_ PER7_ MOB7_ NPHB7_2005 – NPHD7_2005

15 Housing Unit Review Use Excel spreadsheet in same format Keep housing units consistent with components Route local comments through FSCPE agency Provide comments in lowest level of geography –Summary level 157 in non-MCD states, 071 in MCD states

16 The Subcounty Population Estimates Review File File will be made available In February Three to four weeks for review File can not be shared with local governments

17 Subcounty Population Estimates Review File VACR_2000 = Census 2000 Vacancy Rate PPH_2000 = Census 2000 Population per Household HU_2005 = 2005 Housing Unit Estimate GQ_2005 = 2005 Group Quarters Population Estimate

18 Subcounty Population Estimates Review File HHPOP_2005 = 2005 subcounty population estimate –HHPOP_2005 = HU_2005 * PPH_2000* ((100 – VACR_2000)/100) * RAKE_2005 POPCEN_2000 = Census 2000 total population PBASE_2000 = 2000 Estimates base population –Census 2000 population updated with County Question Resolution Actions, boundary changes, and administrative geographic revisions.

19 Subcounty Population Estimates Review File POP_2005 = HHPOP_ GQ_2005 RAKE_2005 = County population estimate/ county sum of uncontrolled subcounty housing unit population estimates –A rake factor less than 1 indicates faster housing unit growth than population growth

20 Subcounty Population Estimates Review Comments should be as specific as possible –Most changes should have already been made to the housing unit file –If housing units are OK and the county estimate is OK then problems should be limited to GQ or calculations

21 Questions ?