Katrina Demographics – A Claritas Assessment of Change

By Hal Reid

On Tuesday, March 7, Claritas hosted a WebEx presentation on Hurricane Katrina, highlighting the resulting shifts in demographics (consumers being relocated, moving away or being otherwise displaced).

One of the standard things marketers do is keep tabs on where the customers are located, their characteristics and how best to market to them. But when major events such as Hurricane Katrina occur which cause major population shifts and affect your customer base, there are new challenges in knowing where your customers are. Are they still in the same geographies? Did they relocate and if so, where?

Claritas did some very interesting work in analyzing the demographics which revealed the changes in population in the areas impacted by Katrina, from a pre-Katrina, post-Katrina and population recovery perspective. They have published comprehensive data on this topic.

Claritas created three population-in-time views for the hurricane-impacted areas: pre-hurricane, post-hurricane (October 2005) and a “recovery time” of January 1, 2006. Population loss was estimated based on FEMA (Federal Emergency Management Agency) flood damage. Claritas then overlayed this information at the block level. This information was also supplemented with Red Cross data on destroyed housing units and FEMA data on claims for assistance (by county).

The January 1, 2006 numbers were difficult to evaluate as they involved not just the population in place but also those returning. This last group (returnees) proved difficult to measure and could only be estimated based on FEMA trailer placements and contacts with demographers in the area.

Population Estimates
The following tables show the estimates of population shift. (Note: These are from the web site.) The first two charts are based on the post-hurricane (October 2005) data.

Top 5 Counties with the highest increase in population immediately after Hurricane Katrina. (Click for larger image)

Top 5 Counties with highest decrease of population immediately after Hurricane Katrina. (Click for larger image)

The numbers in red show greatest increase/decrease in population. Note that while Harris County (Houston) increased by 41,095 people, it was only a 1.1% increase in a population pool of 3.7 million.

When you look at the percentage of population lost, the numbers become more dramatic. Look at these decreases in population.
  • Orleans Parish loses 79%
  • St. Bernard Parish loses 95.9%
The initial demographic impact (again, October 2005 data) can be seen in this thematic map. Note the green areas.

(Click for larger image)

The initial population recovery (Jan 2006) looks like this.

(Click for larger image)

The updated impact is depicted below. Claritas defines the “updated population impact” as “the overall impact … comparing non-hurricane-adjusted population estimates for 2006 to those accounting for the storm's impact.”

(Click for larger image)

These are the counties that were the most affected – those that have significant negative population growth.

(Click for larger image)

Claritas identified a total of 140 counties across the US that were impacted by Hurricane Katrina. When you total the population added to those 132 counties (140 total counties less the eight counties in the table above), the total population shift appears to be about 423,800 people. These 132 counties range across the U.S. Remember, these numbers are all estimates and the actual totals may be higher.

It is always difficult to assess the total impact of a major disaster. The Claritas data shows a net loss to the hurricane-affected area of almost a half-million people. Beyond the loss of property, this represents significant loss in revenue; both tax-based and retail-based. While it is true that this population has been reattributed to 132 other counties, the effect on the regional economy will probably be both felt and studied for a very long time.

Published Wednesday, April 19th, 2006

Written by Hal Reid

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