June 2, 2017


Talk will cover:

  • Motivation and Research Question
  • Data
  • Empirical Strategy
  • Results
  • Economic Relevance

Motivation and Research Question

Growing Risks of Natural Disasters

  • Climate change implies more frequent and more damaging disasters (Van Aalst 2006)
  • Disasters do not discriminate with respect to wealth, but institutions and wealth helps mitigate deaths (Kahn 2005)
  • Growing fiscal and social costs within the United States
    • More frequent FEMA disaster declarations
    • Higher federal costs for declared disasters
    • Non-disaster government transfers increases may understate true cost (Deryugina 2016)

Out of the Frying Pan?

  • Some evidence that people move after big disasters
    • Boustan et al. (2017)
    • Carleton and Hsiang (2016)
  • Rational actors respond to disasters by moving to new locations
    • Because their homes are destroyed?
    • Because the local economy is harmed?
    • Because they have updated their priors about risks?
  • Move people out of dangerous areas, but does this lower future disaster costs?
  • All else equal, higher exposure areas should see lower migration rates

And Into the Fire?

  • Disaster exposure is spatially correlated
  • Disasters are negative income shocks and long moves are costly
  • People tend to move relatively short distances
  • If disasters induce shorter moves, migration may not lower future disaster costs
  • Shorter moves may not lower costs
    • Key question: where do disaster migrants locate to?
    • And does migration mitigate impacts of disasters or simply rearrange the deck chairs?

Hurricane Katrina


  • Category 3 Hurricane at landing (sustained winds of 100–140 miles per hour)
  • Landed 25 August 2005 in Louisiana
  • Total damage estimated at $108 billion (Knobb, Rhome, and Brown 2005)
  • Deaths appear to be at least 1,500 (Beven et al. 2008)
  • Triggered response of over $5.7 billion in FEMA disaster relief

How Did Katrina Affect New Orleans Migrants?

  • Data from IRS county-to-county migration used, tracks filed tax returns at FIPS code from year to year
  • Typical outmigration from New Orleans area from 2000 to 2010 excluding 2005 averaged 21,482 outmigrants per year (average population of 1,421,693)
    • Parishes - Jefferson, Lafourche, Orleans, Plaquemines, St. Bernard, St. Charles, St. John the Baptist, and St. Tammany, and Terrebonne
    • Fairly stable spatial distribution - nearby and large metro regions
  • In 2005, total of 181,854 outmigrants
    • Similar spatial pattern exists plus evident overflow