Changes in SoVI®
SoVI® 2010–14 marks a change in the formulation of the SoVI® metric from earlier versions. New directions in the theory and practice of vulnerability science emphasize the constraints of family structure, language barriers, vehicle availability, medical disabilities, and healthcare access in the preparation for and response to disasters, thus necessitating the inclusion of such factors in SoVI®. Extensive prior testing of SoVI®, along with the introduction of the U.S. Census Bureau’s five-year American Community Survey estimates, permits changes to the SoVI® recipe, resulting in an overall more robust metric.
The tables below detail modifications in the base variables used to compute SOVI®. These tables listed in chronological order describe the current version of SoVI® with its 29 variable set for counties (Table1), and changes from the original 32-variable set used in 2000 (Table 2). The variable set is the same for both county-level analyses and tract-level analyses with two exceptions: in county analyses QMORTBRDN is omitted, and for census tract analyses HOSPTPC is omitted but everything else stays the same maintaining N=29 input variables.
As vulnerability science evolves, no doubt SoVI® will as well. Future directions for
SoVI® include the consideration of pets, homeless populations, physical mobility constraints,
prescription drug dependence, and social capital all at finer spatial scales.
Table 1 List of SoVI® Variables (n=29).
Daggers indicate new variables added since 2010.
| Variable | Description |
|---|---|
| QASIAN | Percent Asian |
| QBLACK | Percent Black |
| QHISP | Percent Hispanic |
| QNATAM | Percent Native American |
| QAGEDEP | Percent Population under 5 Years or 65 and Over |
| QFAM † | Percent Children Living in 2-Parent Families |
| MEDAGE | Median Age |
| QSSBEN | Percent Households Receiving Social Security Benefits |
| QPOVTY | Percent Poverty |
| QRICH | Percent Households Earning over $200,000 Annually |
| PERCAP | Per Capita Income |
| QESL | Percent Speaking English as a Second Language with Limited English Proficiency |
| QFEMALE | Percent Female |
| QFHH | Percent Female Headed Households |
| QNRRES | Nursing Home Residents Per Capita |
| HOSPTPC | Hospitals per Capita (County Level ONLY) |
| QNOHLTH † | Percent of Population without Health Insurance |
| QED12LES | Percent with Less than 12th Grade Education |
| QCVLUN | Percent Civilian Unemployment |
| PPUNIT | People per Unit |
| QRENTER | Percent Renters |
| MDHSEVAL | Median Housing Value |
| MDGRENT | Median Gross Rent |
| QMOHO | Percent Mobile Homes |
| QEXTRCT | Percent Employment in Extractive Industries |
| QSERV | Percent Employment in Service Industry |
| QFEMLBR | Percent Female Participation in Labor Force |
| QNOAUTO † | Percent of Housing Units with No Car |
| QUNOCCHU † | Percent Unoccupied Housing Units |
| QHSEBRDN † | Percent of All Households Spending More than 40% of Their Income on Housing Expenses (Tract Level ONLY) |
Table 2: Thirty-two original SoVI® variables, descriptions, and changes in SoVI® 2000
| Variable | Description | Changes from SoVI®2000 to SoVI®2006-10 |
|---|---|---|
| QASIAN | Percent Asian | — |
| QBLACK | Percent Black | — |
| QSPANISH | Percent Hispanic | Renamed QHISP |
| QINDIAN | Percent Native American | Renamed QNATAM |
| QKIDS | Percent Kids | Omitted and replaced by QAGEDEP=Percent of population under 5 years and 65 or older |
| QPOP65O | Percent of Population over 65 | Omitted and replaced by QAGEDEP |
| MEDAGE | Median Age | — |
| QSSBEN | Percent Social Security Beneficiaries | Percent of Households Receiving Social Security Benefits (formerly Individuals) |
| QPOVTY | Percent Poverty | — |
| QRICH | Percent Households Earning over $100,000 annually | Percent of Households Earning over $200,000 (formerly $100,000) |
| PERCAP | Per Capita Income | — |
| QMIGRA | Percent of Foreign Born Who Are Recent Migrants | Omitted and replaced with QESL=Percent Speaking English as a Second Language |
| QFEMALE | Percent Female | — |
| QFHH | Percent Female Headed Households | — |
| NRRESPC | Nursing Home Residents per Capita | Modified to QNRRES=Percent of Population Living in Nursing and Skilled-Nursing Facilities (formerly computed as per capita) |
| HOSPTPC | Hospitals per Capita | Omitted at Block Group and Tract Levels |
| PHYSICN | Number of Physicians per 10,000 People | Omitted |
| QED12LES | Percent with Less than 12th Grade Education | — |
| QCVLBR | Percent in Civilian Labor Force | Omitted |
| QCVLUN | Percent Civilian Unemployment | — |
| QURBAN | Percent Urban Population | Omitted |
| QFRM | Percent of Population on Rural Farms | Omitted |
| PPUNIT | People per Unit | — |
| QRENTER | Percent Renters | — |
| HODENT | Housing Density | Omitted |
| MHSEVL | Mean Housing Value | Omitted and replaced by MDHSEVAL (Median House Value) |
| MCRENT | Mean Contract Rent | Omitted and replaced by MDGRENT (Median Gross Rent) |
| QMOHO | Percent | — |
| QAGRI | Percent Employment in Extractive Industries | Renamed QEXTRCT |
| QSERV | Percent Employment in Service Industry | — |
| QTRAN | Percent Employment in Transportation & Public Utilities | Omitted |
| QFEMLBR | Percent Female Participation in Labor Force | — |