Surviving Natures Most Surviving Natures Most Powerful Storm: Cost Powerful Storm: Cost Effective Methods to Effective Methods to

Reduce Tornado Reduce Tornado CasualtiesCasualties

Kevin M. Simmons, Ph.D.Kevin M. Simmons, Ph.D.Austin CollegeAustin College

Daniel Sutter, Ph.D.Daniel Sutter, Ph.D.Troy UniversityTroy University

Economic and Economic and Societal Impacts Societal Impacts of Tornadoesof Tornadoes

By Kevin M. Simmons and Daniel By Kevin M. Simmons and Daniel SutterSutter© 2010, 296 pages in paperback© 2010, 296 pages in paperbackISBN: 978-1-878220-99-8ISBN: 978-1-878220-99-8

AVAILABLE February 2011AVAILABLE February 2011from the American Meteorological from the American Meteorological Society and the University of Society and the University of Chicago Press Chicago Press

Killer Tornadoes of 2011Killer Tornadoes of 2011

• Average annual Average annual number of killer number of killer tornadoes 2000-tornadoes 2000-20102010– 2121

• Number of killer Number of killer tornadoes 2011tornadoes 2011– 5858

May 22, 2011 – Joplin May 22, 2011 – Joplin MissouriMissouri

• Tornado struck at 5:41 p.m. on Tornado struck at 5:41 p.m. on Sunday, May 22, 2011Sunday, May 22, 2011

• Rated EF-5Rated EF-5• EF-5 strength for a length of 6 miles EF-5 strength for a length of 6 miles

and ¾ mile wideand ¾ mile wide• 161 Fatalities and over 1000 injuries161 Fatalities and over 1000 injuries• Single worst casualty total since Single worst casualty total since

records began in 1950records began in 1950

Street in Joplin – BeforeStreet in Joplin – BeforeGoogle Street LevelGoogle Street Level

Same Street in Joplin - AfterSame Street in Joplin - After

How to Survive Such a How to Survive Such a StormStorm

• Winds from an EF-5 Winds from an EF-5 tornado will destroy tornado will destroy almost anything in almost anything in it’s path.it’s path.

• To survive, you To survive, you must be in a must be in a hardened hardened (engineered) room (engineered) room or shelter.or shelter.

Comparing Benefits versus Comparing Benefits versus CostCost

• When faced When faced with such with such tragedy, we tragedy, we are reminded are reminded that life is that life is priceless.priceless.

The TradeoffThe Tradeoff

• Such a large event prompts discussion of Such a large event prompts discussion of public subsidies for saferooms.public subsidies for saferooms.

• Several states, most notably Oklahoma Several states, most notably Oklahoma have had such programs.have had such programs.

• If public funds are used, there exists a If public funds are used, there exists a tradeoff on potential uses of the same tradeoff on potential uses of the same money to save lives elsewhere.money to save lives elsewhere.

• Value of Life estimates:Value of Life estimates:– A common range is $5-$10 million A common range is $5-$10 million

Our ApproachOur Approach

• For each state we have calculated For each state we have calculated a “Cost Per Avoided Fatality”a “Cost Per Avoided Fatality”

• Inputs to the calculation:Inputs to the calculation:– Average annual fatalitiesAverage annual fatalities– Average shelter costAverage shelter cost– Housing UnitsHousing Units– Discount RateDiscount Rate– Estimated shelter lifeEstimated shelter life

Example: AlabamaExample: AlabamaPermanent HomesPermanent Homes

• Housing Units (2010 Census – Single Detached)Housing Units (2010 Census – Single Detached)

1,535,1461,535,146

• Average Annual Fatalities (1950-2011)Average Annual Fatalities (1950-2011)

3.073.07

• Shelter CostShelter Cost

$2,500$2,500

• Shelter LifeShelter Life

50 Years50 Years

• Discount RateDiscount Rate

3%3%

Example: AlabamaExample: AlabamaMobile HomesMobile Homes

• Housing Units (2010 Census)Housing Units (2010 Census)

291,373291,373

• Average Annual Fatalities (1950-2011)Average Annual Fatalities (1950-2011)

4.264.26

• Shelter CostShelter Cost

$2,500$2,500

• Shelter LifeShelter Life

50 Years50 Years

• Discount RateDiscount Rate

3%3%

Estimate Cost Per Avoided Estimate Cost Per Avoided FatalityFatality

• Permanent HomesPermanent Homes

$47.2 Million$47.2 Million

• Mobile HomesMobile Homes

$6.5 Million$6.5 Million

Estimate Cost Per Avoided Estimate Cost Per Avoided Fatality With Some Fatality With Some

Consideration for Peace of Consideration for Peace of MindMind

• Permanent HomesPermanent Homes

$22.2 Million$22.2 Million

• Mobile HomesMobile Homes

$3.0 Million$3.0 Million

Observations on Public Observations on Public FundingFunding

• There appears some There appears some merit for mobile merit for mobile homes given the homes given the increased vulnerabilityincreased vulnerability

• Permanent homes, Permanent homes, however, are harder to however, are harder to justifyjustify

Private MitigationPrivate Mitigation

• One way to examine the value of One way to examine the value of saferooms is to see if they affect the saferooms is to see if they affect the value of the propertyvalue of the property

• Study: Study: Oklahoma County Oklahoma County Residential Residential SalesSales

• We were looking for any premium to We were looking for any premium to sales price if a shelter was presentsales price if a shelter was present

Private MitigationPrivate MitigationResultsResults

• The presence of a The presence of a shelter added shelter added about 3.5% to the about 3.5% to the sales price of the sales price of the homehome

• For our sample that For our sample that was an increase of was an increase of $4,200 to the $4,200 to the average homeaverage home

Effectiveness of NWS Effectiveness of NWS Tornado WarningsTornado Warnings

• One easy One easy comparison to test comparison to test the effectiveness the effectiveness of warnings is to of warnings is to examine two years examine two years 1953 and 20111953 and 2011

Effectiveness of NWS Effectiveness of NWS Tornado WarningsTornado Warnings

• 19531953519 Fatalities519 Fatalities

41 Killer Tornadoes41 Killer Tornadoes

72 Affected counties72 Affected counties

78% F-3 or Higher78% F-3 or Higher

• 20112011544 Fatalities544 Fatalities

58 Killer Tornadoes58 Killer Tornadoes

90 Affected counties90 Affected counties

79% EF-3 or Higher79% EF-3 or Higher

Fatality RateFatality Rate

• 19531953Population of Affected Population of Affected

CountiesCounties3.9 Million3.9 Million

Fatality RateFatality Rate131.7 per million131.7 per million

• 20112011Population of Affected Population of Affected

CountiesCounties8.6 Million8.6 Million

Fatality RateFatality Rate64.3 per million64.3 per million

Continued Progress in Continued Progress in Reducing CasualtiesReducing Casualties

• Nocturnal TornadoesNocturnal TornadoesA lethal tornado at 2:00 a.m. will kill A lethal tornado at 2:00 a.m. will kill

over over twice as many people as the same twice as many people as the same tornado tornado occurring at 2:00 p.m.occurring at 2:00 p.m.

• False AlarmsFalse AlarmsOur research shows that there is a Our research shows that there is a

“cry wolf” “cry wolf” effect.effect.

Thank You For Your Attention