"In some Mississippi Gulf Coast towns, Katrina's powerful 28-foot-high storm surge did not leave a single structure standing. There was nothing for evacuees to return to. The destruction of housing and infrastructure in St. Bernard Parish, a low-lying 40-mile-long peninsula extending southeast from New Orleans, rendered most of it uninhabitable.
Many evacuees were able to return in a matter of days, but many more were not. New Orleans' population before Katrina struck was 463,000. Claritas, a private demographic data-gathering and analysis firm, reported that after the hurricane New Orleans' population shrank to 93,000. By January 2006, it had recovered to 174,000. By July 2006, the city still had only 214,000 residents, less than half of its pre-Katrina population.
...After a point -- as storm risks multiply and insurance rates rise -- real estate prices start to decline. To cite an extreme example, how much is a building lot worth in St. Bernard Parish, now largely abandoned, or in the low-lying parts of New Orleans?
As rising seas and more powerful hurricanes translate into higher insurance costs in these coastal communities, people are retreating inland. And just as companies migrate to regions with lower wages, they also migrate to regions with lower insurance costs."