Hurricanes Katrina, Rita, and Wilma had significant impact along the Gulf and Atlantic Coasts.  While many businesses were in the path of these storms, some were affected and others were not.  Knowing where affected businesses are concentrated can guide efforts by Federal, State, and local agencies, service organizations, and entrepreneurs to respond to the storms and rebuild the economies of these areas.
 

 Maps of Affected Areas and Establishments -- Explanatory Notes

The maps listed on this site show the FEMA-designated damaged areas affected by Gulf Coast and Atlantic Coast Hurricanes, and estimates of the percent of affected businesses within FEMA-designated damaged areas by Census Block. Maps are provided for Hurricanes Katrina, Rita and Wilma. Percentages refer only to establishments that could be geographically coded to latitude and longitude.  Not all establishments are latitude and longitude coded so the percentages shown are approximations of the actual percentages. The methodology for creating these estimates is the following. We overlay FEMA remote sensing Geographic Area System (GIS) damage-level maps on Census Blocks. We can then identify affected businesses by overlying establishments within particular Blocks. For any given Block it is then possible to identify the percentage of establishments that are damaged and those that are not.  The maps reflect the number of businesses and their employees that were located in the affected areas prior to the storms (in calendar year 2003) based on the Census Bureau's Business Register.

Geocoding quality can affect estimates particularly if there are few establishments operating in a particular Block. That is, the estimate for a Block with few establishments can be significantly affected by an uncoded establishment or two. Examination of boundary Blocks indicates estimates are reasonable. Blocks that lie entirely within a damage area typically have a higher share of affected businesses compared to those that don't.  Geocoding quality does not seem to vary much across Blocks within the areas we are looking at. 

Tables of Affected Areas and Establishments -- Explanatory Notes

The tables listed on this site tables show estimates of the number of businesses and the employment at businesses affected by Hurricanes Katrina (Tables 1A and 1B), Rita (Tables 2A and 2B) and Wilma (Tables 3A and 3B).  The first row of each table shows the total number of establishments (or employment) in the states impacted by the hurricane being analyzed. The second row of each table shows the number of establishments (or employment) for which we are able to assign latitude and longitude coordinates.  These detailed geocodes are needed to determine whether the business establishment lies within a Federal Emergency Management Agency (FEMA) designated hurricane damage zone (definitions of FEMA damage zones are available at http://www.gismaps.fema.gov/attr.shtm).

The remaining rows of the “A” tables give the percentage of geocoded businesses that are located within affected areas using various definitions.  Likewise, the remaining rows of the “B” tables give the percentage of employees at geocoded businesses within affected areas using various definitions.  These definitions are whether the business establishment is located within: a county or parish that was declared as a federal disaster area /1; a county that contained at least one FEMA designated damage zone; a Metropolitan or Micropolitan Statistical Areas (MSA) or Place containing at least one FEMA designated damage zone; a Census Block containing at least one FEMA designated damage zone; or a FEMA designated damage zone.

Using smaller geographic units to determine whether a business establishment is located within a hurricane affected area gives smaller estimates of the number (or employment) of affected businesses.  Note that we are only looking at direct affects to businesses in terms of physical damage.  Economic affects due to lost customers or displaced employees are not considered here.

We only report the percentage of affected businesses and employees for the set of business establishments for which we have detailed geocodes.  One can obtain a lower bound estimate of the number (or employment) of affected businesses by multiplying these percentages by the numbers given in the second row of each table.  For example, the lower bounds of businesses affected by Hurricane Katrina, as defined by being located within a FEMA damage zone, are 13,265 for Louisiana, 2665 for Mississippi and 53 for Alabama (rounding down).

There are likely to be many affected businesses that are not geocoded.  One can put an upper bound on the number (or employment) of affected businesses by assuming all business in counties with some FEMA designated damage zones are affected and adding this to the lower bounds provided in the previous paragraph.  For example, the number of uncoded businesses in Louisiana, Mississippi and Alabama in counties/parishes with some FEMA designated damage zones is 14,496, 2322 and 6005 respectively (these numbers are not listed in the tables).  Thus, the upper bound for the number of businesses affected by Hurricane Katrina is 27,761 for Louisiana, 4987 for Mississippi and 6058 for Alabama.  A quick glance at the maps of FEMA damage areas confirms that it cannot be the case that all uncoded business are located in FEMA damage zones, since these zones occupy only a small amount of area within any county or parish.  Work is underway to estimate the number and employment of damaged but ungeocoded businesses.  These estimates will appear in a forthcoming Center for Economic Studies working paper that will be available at www.ces.census.gov.  

1/  A federal disaster area is declared in a Federal Disaster Declaration. A declaration makes federal assistance available to State and local governments as well as citizens affected by disaster (http://www.fema.gov/rrr/dec_guid.shtm). See http://www.fema.gov/news/disasters.fema for a list of 2005 FEMA Federal Disaster Declarations as well as maps associated with Hurricanes Katrina, Rita and Wilma.