Migration Patterns and Mover Characteristics
from the 2005 ACS Gulf Coast Area Special Products
Kin Koerber
Housing and Economic Household Statistics Division
U.S. Census Bureau
Presented at the Southern Demographic Association Conference
Durham, North Carolina
November 2-4, 2006
This report is released to inform interested parties of ongoing research
and to encourage discussion. The views expressed on statistical, methodological,
technical, or operational issues are those of the author and not necessarily
those of the U.S. Census Bureau.
Introduction
Hurricane Katrina devastated the New Orleans and Mississippi Gulf Coast
areas when it struck land on August 29, 2005. Almost four weeks later,
on September 24, Hurricane Rita made landfall near the Louisiana-Texas
border. The widespread damage caused by Katrina, and to a lesser extent
Rita, uprooted thousands of people and changed the demographic, social,
and economic face of the areas in the paths of the storms as well as those
areas that saw great influxes of people escaping the destruction.
In order to measure the effects the hurricanes had on the population
and housing in the area, the U.S. Census Bureau released the 2005 American
Community Survey (ACS) Gulf Coast Area Special Products in June 2006.
Two sets of estimates were produced to provide a picture of the population
and housing units for Alabama, Louisiana, Mississippi, and Texas for the
8 months before and 4 months after Katrina and Rita. The migration estimates
produced at that time were for where people currently lived and did not
contain information on the specific location of their previous residences.
This analysis uses data from the 8-month (before) and 4-month (after)
period data sets to determine the migration patterns of those displaced
by the hurricanes. We will look at people whose residence 1 year ago was
in specific county groups within the Federal Emergency Management Agency
(FEMA) areas of the four states most affected by the hurricanes and determine
mobility rates to other areas within the FEMA areas, the remainder of
each of the four states, and the remainder of the U.S. Along with the
migration flows, mover characteristics will be examined. Additional analysis
will focus on the quality of the data by comparing the 8-month estimates
to the 2004 ACS.
Data
The ACS gathers data from every county in the United States in order
to produce annual estimates of population and housing characteristics
for places with a population of 65,000 or more. The annual initial sample
size is about 3,000,000 addresses that are allocated to the 12 months
of the sample year, so it is possible to create estimates for partial
years. For the Gulf Coast Area Special Products, the national sample size
consists of approximately 1,945,000 addresses for the data collected for
January through August and approximately 977,000 addresses for September
through December. Both samples were weighted to give estimates for a full
year period. In this product, only areas with 300 or more interviewed
housing units were published.
The ACS Special Products focuses on the 117 counties and parishes in
Alabama, Louisiana, Mississippi, and Texas designated by the FEMA as receiving
“individual and public assistance” as of October 7, 2005 for
Hurricane Katrina and October 20, 2005 for Hurricane Rita. Also included
are estimates for the remaining counties outside the FEMA designated areas
for each of the four states.
The 2005 ACS only surveyed people in households and not in group quarters.
People who were incarcerated or living in nursing facilities, mental hospitals,
college or university housing, homeless shelters, or other group quarters
facilities are not included in the estimates.1
Also, the 2005 ACS sample was selected from an address list developed
early in 2005 and therefore the estimates do not reflect any housing added
to the address list after that date. Those people who moved out of the
area and into shelters or makeshift housing are not represented in the
estimates.
Normally, ACS household population totals are controlled at the county
level to the annual mid-year estimates produced independently from ACS
by the Census Bureau. Since the 2005 population estimates are for July
1, well before either hurricane occurred, the ACS Special Products household
populations are not controlled. Instead, the estimates are calculated
by summing the final weights for each person or household. Whenever possible,
ratios will be used for comparisons rather than the number of people or
households.
The mobility question on the ACS asks where the respondent lived 1 year
ago. The normal collection period for ACS is a complete year, and therefore
the seasonality of moving does not have to be considered when comparing
annual estimates. This is not the case with the special products estimates
that cover partial years. Changes in residences covered by the 8-month
estimates occurred between January 2004 and August 2005 while the changes
in residences for the 4-month estimates occurred between September 2004
and December 2005. According to the 1996 Survey of Income and Program
Participation, most moves occur between June and October, but about 67
percent of moves take place in the first 8 months of the year and 33 percent
take place in the last 4 months.2
Therefore, the seasonality of moves should have little effect on the comparability
among the 2005 ACS special products estimates for mobility. However, the
4-month estimates do include moves that occurred before Hurricane Katrina
was even formed.
Comparison Between 2004 ACS and 2005 ACS Special Products Estimates
It is expected that the mover rate will not significantly change between
the 2004 ACS and the pre-hurricanes 2005 ACS estimate. Conversely, for
the areas directly hit by Katrina and Rita as well as the main destination
points of evacuees, we expect sharp changes in the mover rates between
the 2005 ACS pre- and post-hurricanes estimates.
There are some limitations in comparing 2004 ACS with 2005 ACS Special
Products data. Unlike the 2005 ACS, data for the 2004 ACS were collected
in only 1,240 counties and the total initial sample size was about 838,000.
Because of the smaller sample, estimates are available for only those
counties with a population of 250,000 or more. Another difference is that
the 2005 ACS uses 2004 metropolitan area definitions while the 2004 ACS
uses 1999 metropolitan area definitions. In the case of New Orleans Metropolitan
Area, the 1999 definition includes St. James Parish, but the 2004 definition
does not. Because of these differences, the comparison between 2004 ACS
and 2005 ACS Special Products estimates is limited to the state level.
Table 1 shows the estimated number of people living in the four Gulf
States and the remainder of the United States 1 year ago and currently
living in a household within the United States. The percentage distribution
is given by the type of move for the population: nonmovers, movers within
the same area, and movers to a different area. For comparison purposes,
movers from different areas and movers from abroad are included also as
a percentage of those who lived in an area 1 year ago and currently in
the United States.
The 2004 and 2005 8-month estimates for those who lived in an area 1
year ago are statistically different because the 2004 data are controlled
to independent population estimates and the 2005 Gulf Coast estimates
are not controlled. The percent of nonmovers and movers within Texas do
have significant changes at the 90 percent confidence level of 0.9 percentage
point each, but a slight change is not unexpected. Neither set of numbers
is significant at the 95 percent level.3
The comparison between the 2005 8-month and 4-month estimates does show
a change in migration patterns. The percent of the people who lived in
Louisiana 1 year ago that moved differed from 15.4 percent for the pre-hurricanes
estimates to 23.1 percent for the post-hurricanes estimates. Mississippi
showed a similar change from 14.8 percent to 19.5 percent. Both states
had significant changes in percent of movers to a different area and within
the same area. The percent of movers from Louisiana to a different area
increased from 2.1 percent to 8.1 percent and for Mississippi, the percent
of movers to a different state increased from 2.5 percent to 4.4 percent.
The percent of movers within Louisiana increased from 13.3 percent to
15.0 percent while the percent of movers within Mississippi increased
from 12.3 percent to 15.1 percent. Texas and the remainder of the United
States experienced the opposite trend. Texas showed an increase in the
percentage of movers from a different state from 2.0 percent to 2.9 percent.
The U.S. showed an increase in the percentage movers from the four Gulf
States from 0.2 to 0.3. As expected, the estimates do record a change
in migration patterns between the 2005 ACS 8-month and 4-month estimates
with an increase in movers from the states directly hit by the hurricanes
to other states, especially Texas.4
Migration Patterns of Selected Areas
Since it is established that the ACS estimates are robust enough to show
the change in migration patterns caused by the storms at the state level,
the next step is to determine what information the estimates can provide
at geographic levels below that. The Special Area Products divided the
117 designated FEMA counties into 59 areas of which some overlapped. For
this analysis only a few of the Gulf Coast Special Area Products areas
or combination of the areas will be examined. Two of the areas are the
New Orleans Metropolitan Area and the three Mississippi Gulf Coast counties
that were struck by Hurricane Katrina. Lake Charles, Louisiana and Beaumont-Port
Arthur, Texas Metropolitan Areas are included because they were in the
path of Hurricane Rita. The Houston area and the Baton Rouge Metropolitan
Area are included due to the large number of people settling there from
those areas hardest hit. The other areas consist of the remaining designated
FEMA counties in each of the four states, the remaining counties in those
states, and the rest of the United States for a total of 15 areas. Table
2 lists the FEMA designated counties within each area along with the January
1, 2006 population estimates published by the Census Bureau.
Table 3 shows similar estimates for the 15 areas that Table 1 shows for
the states: namely, the percent of nonmovers, movers within the same area,
movers from a different area within the same state, movers to a different
area within the same state, movers from a different area of a different
state, movers to a different area of a different state, and movers from
abroad based on the estimated number of people living in an area 1 year
ago and currently living in a household within the United States.
New Orleans, Gulfport-Biloxi, and the remainder of the U.S. had significant
decreases in the percent of nonmovers between the 8-month and 4-month
estimates. The largest difference was New Orleans, which went from 86.5
percent to 55.1 percent. Gulfport-Biloxi decreased by from 83.6 percent
to 67.1 percent and the remainder of the U.S. from 84.9 to 84.3. Beaumont-Port
Arthur decreased between the 8-month and 4-month estimates; however, the
difference was not statistically significant.5
Movers from a different area within the same state changed significantly
for four of the five areas in Louisiana. New Orleans had the only decrease
from an 8-month percent of 1.0 to 0.3 percent for the 4-month. Baton Rouge
increased from 1.4 to 7.6, the other designated FEMA counties in Louisiana
increased from 1.4 to 3.8, and the remainder of Louisiana increased from
0.7 to 2.8.6
Four areas had significant differences in the movers from a different
area in a different state between the two sets of estimates. The other
designated FEMA counties in Mississippi increased from 1.8 percent for
the 8-month to 3.3 percent for the 4-month, the Houston area increased
from 2.0 percent to 3.4 percent, the remainder of Texas increased from
2.1 percent to 2.7 percent, and the remainder of the U.S. increased from
0.2 percent to 0.3 percent.7
New Orleans, the only area to show a significant change for movers to
a different area of the same state, went from 0.9 for the 8-month percentage
to 8.0 for the 4-month percentage. New Orleans, along with Gulfport-Biloxi,
had significant increases for movers to a different state. New Orleans
increased from 2.1 for the 8-month percentage to 24.1 for the 4-month
percentage. Gulfport-Biloxi increased from 4.1 to 10.7.8
In order to examine exactly where people left and relocated, Table 4
shows the mover flows between the 15 areas. There were significant positive
increases between the 8- and 4-month percent of movers from New Orleans
to Houston, Baton Rouge, the remainder of Texas, and the remainder of
the United States. The 8-month estimates showed that 78.1 percent of movers
who lived in the New Orleans MSA stayed in the New Orleans area, but only
28.4 percent of movers in the 4-month estimates did so. The 4-month estimates
also showed that 20.6 percent of the movers went elsewhere in the U.S.,
14.5 percent went to the Houston area, 11.6 percent went to the remainder
of Texas, and 8.1 percent went to the Baton Rouge MSA. The percent of
movers who lived in New Orleans 1 year ago and currently live in the remainder
of Alabama also was significant, but the percent increased only from 0.1
for the 8-month estimates to 1.2 for the 4-month estimates.9
The other significant difference was the percent of movers who lived
in the other FEMA designated counties in Texas and currently live in the
Houston area. The percent decreased from 17.7 for the 8-month estimates
to 4.4 for the 4-month estimates. This could indicate that because of
an increase in housing demands by the influx of movers from New Orleans
into the Houston area, people from other nearby parts of Texas could not
find housing as readily in the Houston area as before.
The ACS migration patterns in and out of the selected areas do show the
effect that Hurricane Katrina had on both the New Orleans and Gulfport-Biloxi
areas and the movement to elsewhere in Louisiana and Texas. The same cannot
be said of the areas that were hit by Hurricane Rita. Neither the Beaumont-Port
Arthur area nor the Lake Charles MSA had changes that were significant
at the 90 percent level. When determining where the movers relocated,
the ACS estimates were robust enough to register those from the New Orleans
MSA but not for any of the other areas.
Mover Characteristics for New Orleans
There were enough movers that lived in New Orleans 1 year ago for the
4-month ACS to examine some characteristics of those movers. To produce
reasonable estimates, the Gulf Coast Area Special Products used the criterion
of only publishing profiles for areas that had a sample size of 300 or
more households. The same criterion was used when selecting the subgroups
of movers based on their current residence. In New Orleans, there were
enough movers in the 4-month period to examine characteristics for nonmovers,
movers within the New Orleans MSA, movers to the remainder of the FEMA
designated area, and movers to the remainder of the United States. Table
5 shows the results for those groups along with the population 1 year
and over for the 8-month period. This gives a picture of the population
of the New Orleans MSA before Hurricane Katrina hit, as well as those
that lived in the MSA 1 year prior and moved to nearby areas and areas
further away. Table 6 is a condensed version of Table 5 in which the nonmovers
and movers within the New Orleans MSA are combined and the movers to outside
the MSA are also combined.
Not surprisingly, the population that stayed in the New Orleans area
is older. The median age based upon the 8-month estimates was 38.5. The
median age for those who stayed in the New Orleans MSA was 42.2 and those
that moved outside the MSA was 29.5.
Those who stayed in the New Orleans MSA also had a difference in median
ages between the movers and nonmovers. The median ages were 44.3 for nonmovers
and 32.2 for movers.
Relationship to the householder varied between those that stayed and
those that moved. For any person who stayed, a higher percentage, 39.8
percent, were householders than the 31.9 percent of those who moved out
of New Orleans who were householders. Among those who left, a higher percentage
was extended family members (19.0 percent) or nonrelatives (9.7 percent)
than those who stayed (9.1 and 5.4, respectively).
Relationship also varied for those who did not leave New Orleans. Before
Katrina came, 11.4 percent of the population 1 year and over were extended
family or nonrelatives for the nonmovers. After Katrina, 8.1 percent of
the nonmovers were extended family or nonrelatives while 42.8 percent
of the movers within New Orleans were extended family or nonrelatives.
The vast majority of households in New Orleans before Katrina hit contained
only people that lived in the New Orleans MSA 1 year prior. This was also
the case for those that stayed in the New Orleans area in the 4-month
estimates. However, 26.2 percent of those who moved outside the MSA have
at least one person in the current household that lived outside New Orleans
1 year ago.
The data before Katrina hit showed that the average household size was
2.42. After the hurricane, the average household size for those who stayed
in New Orleans was not significantly different, but for those who left
the area, it was 3.16. Of the 3.16, an average of 2.21 persons in those
households actually lived in New Orleans one year ago. There is an overlap
between households with nonmovers and movers within New Orleans. Of the
households with movers within New Orleans, 43.5 percent also contained
nonmovers, and those households are included in the calculations for both
groups.
Before Katrina, 68.2 percent of the population 1 year and over lived
in an owner-occupied housing unit. After Katrina, a larger proportion
of the population, 78.3 percent, were living in an owner-occupied housing
units in New Orleans MSA. Only 23.6 percent of those who moved out of
the area were living in an owner-occupied housing unit. This suggests
that people in owner-occupied housing units were more likely to stay than
those in renter-occupied housing units.
Those who were married or widowed tended to stay more than those separated
or never married. Before Katrina, 46.3 percent of the population 15 years
and over were married, 7.7 percent were widowed, and 31.8 percent never
married. Except for those never married, there was not a significant difference
in distribution for those who stayed. The percentage of those who never
married decreased to 26.2. Of those who moved away, the percentages for
married decreased to 34.6 and widowed decreased to 4.7. The percentage
for never married increased to 43.9.
Those who stayed in the area were more likely to be unemployed or not
in the labor force. Before Katrina hit, 41.0 percent of the population
16 years and over were unemployed or not in the labor force. After Katrina,
New Orleans had a higher percent, 47.8 percent, of people who were unemployed
or not in the labor force. Of those who moved elsewhere, 63.8 percent
were unemployed or not in the labor force. Likewise, a higher percentage
of the movers were in poverty. The percent of people who lived in poverty
for those who stayed was 12.9 and for those who left was 32.2.
The racial makeup of the MSA also changed after Katrina. Before Katrina,
non-Hispanic Whites made up 54.6 percent of the MSA population 1 year
and over. Of those who stayed within the MSA, 66.8 percent of the population
1 year and over was non-Hispanic White, but those that moved out of the
MSA were 32.1 percent non-Hispanic White. Likewise the Black or African
American population dropped from 35.7 percent of the population 1 year
and over to 21.5 percent. African Americans represented 59.3 percent of
the movers out of the MSA. Other race and ethnic groups were too small
to show any significant change.
There are no significant differences in percent disabled, school enrollment,
and educational attainment between those who relocated outside the New
Orleans MSA and those who stayed.
Mover Characteristics for Whites and Blacks or African Americans
in New Orleans
The sample sizes of non-Hispanic Blacks or African Americans alone and
non-Hispanic Whites alone are large enough that estimates for characteristics
for those who stayed in the New Orleans area and those who left can be
produced for these groups. However, because of the smaller populations,
the margins of errors tend to be greater.
Tables 7 and 8 show in general, the differences between non-Hispanic
Whites who stayed and moved are more pronounced than the differences between
non-Hispanic African Americans who stayed and moved. There is no significant
difference between the median age for the African Americans who stayed
in the New Orleans area and those who moved out of the area. Whites who
stayed tended to be older with a median age of 45.2 years than those who
left with a median age of 31.8 years.
The estimates for household relationship had similar results. For Whites,
a smaller percent of people who moved outside New Orleans were considered
householders (31.9 percent) than those who stayed (42.6 percent). There
were larger percentages for movers outside the area who were extended
family members or nonrelatives of the householder. Among those who moved
out of the area, 29.8 percent were extended family members or nonrelatives
compared with 12.6 percent for those who stayed in the area. African Americans
had no significant differences in household relationship between those
who left and stayed.
Both groups had differences in housing tenure, but the percent of African
Americans who moved out of New Orleans and lived in renter-occupied housing
(85.1 percent) was greater than Whites (60.9 percent).
Marital status also varied between Whites who moved and stayed in the
area. The percentage of the population 15 years and over who stayed and
were married is 55.2 compared to 40.2 for those who moved. Those people
that never married represented 23.0 percent of those who stayed and 40.3
percent of those who moved. The estimates for African Americans are comparable
but not significantly different. Married people make up 36.5 percent of
those that stayed and 30.3 of those that left, while African Americans
that never married represent 37.4 percent of those who stayed and 46.5
of those who left.10
White have higher percentages of unemployed than those who remained in
the New Orleans area. For those who stayed, 5.7 percent were unemployed
while 13.1 percent who left the area were unemployed. For African Americans,
while there was not a significant difference in the percent unemployed
between those who remained and those who left, there was a significant
difference in the percent employed. Of the African Americans who stayed,
45.6 percent were employed while 28.5 percent of those who moved out of
New Orleans were employed.
The percentage of Whites in poverty was greater for those that moved
outside the New Orleans area than those that stayed. For those that moved,
21.4 percent were in poverty while 8.9 percent of those that stayed were
in poverty. The percentage in poverty for African Americans was not significantly
different.
Summary
The American Community Survey has a large enough sample within a survey
year to track migration changes caused by major disasters. In the case
of Hurricane Katrina, the 8-month and 4-month estimates from the 2005
ACS were able to show the change of migration patterns from the New Orleans
MSA and the Mississippi Gulf Coast to other locations. However, the relocation
of people from areas affected by Hurricane Rita was not significant enough
for ACS to track.
For an area the size of the New Orleans Metropolitan Area, the sample
is robust enough to look at characteristics for large subgroups of the
population. The 2005 ACS found that for New Orleans, those that moved
out of the area tended to be more able to leave and had less invested
in the area. Those who moved were younger, more likely to be single or
separated, less likely to be employed or in the labor force, more likely
to be in poverty, and living in renter-occupied housing. Also, within
the New Orleans area and outside, households tended to be combined as
people moved in with extended family members and nonrelatives. The racial
makeup of the area changed as a larger percentage of African Americans
moved out of the area than Whites. Part of the reason is that larger proportion
of Whites may have stayed is because they owned houses and had jobs that
were not lost due to the hurricane. The demographic composition of the
New Orleans Metropolitan Area changed in the months following Hurricane
Katrina. Future ACS data will tell whether or not those changes are temporary
or permanent.
References
Schachter, Jason P. and Jeffrey J. Kuenzi. Seasonality of Moves and the
Duration and Tenure of Residence: 1996. Working Paper Series No. 69. U.S.
Census Bureau, Washington, DC, 2002.
Special Population Estimates for Impacted Counties in the Gulf Coast
Area. U.S. Census Bureau, Washington, DC, 2006.
http://www.census.gov/Press-Release/www/emergencies/impacted_gulf_estimates.html
2005 ACS Special Product for the Gulf Coast Area. U.S. Census Bureau,
Washington, DC, 2006.
http://www.census.gov/acs/www/Products/Profiles/gulf_coast/index.htm
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