We have witnessed a tragic tornado outbreak this week, one for the record books. The fatality total as of this morning now definitely appears to have topped the April 1974 Super Tornado outbreak. The question many people have been asking is why this outbreak was so deadly. As a tornado impacts researcher, the important question is whether the death toll was due to this being a meteorological outlier event, or due to heightened vulnerability. The southeastern U.S. is vulnerable to tornado casualties; meaning that controlling for the strength, timing, and tornado path characteristics, tornadoes in the Southeast kill and injure more people than tornadoes elsewhere. In my recent book on tornado impacts with Kevin Simmons, we estimated state fixed effects for twenty eight states, and constructed a casualty index based on the fixed effects from various specifications. The indexes are based on tornadoes through 2007. A higher value of the index indicates that tornadoes in the state result in more casualties, everything else equal. Here are the index values and ranks (out of 28 states) for the states with fatalities in Wednesday's outbreak:
Alabama 1.63 23
Georgia 2.65 26
Mississippi 0.91 13
Tennseessee 1.78 24
Virginia 0.72 9
The tornado outbreak struck states which historically have been vulnerable. The Southeastern vulnerability is also associated with the off-season, night time, and mobile home vulnerabilities. While we are waiting for the individual tornado paths to be identified and rated, it is hard to draw conclusions about this event. But it does not fit the standard Southeastern vulnerability, as it occurred during the prime tornado season, and during the late afternoon hours. Many of the deaths in Tuscaloosa and Birmingham appear to have been in permanent homes. It appears to have been more of a problem of multiple long track, violent (F4 or F5) tornadoes.
Many observers have been comparing this outbreak with the 1974 Super Outbreak. As a social scientist who studies tornado impacts, it seems that the more significant historical parallel is the 1925 Tri-State Tornado. The Tuscaloosa - Birmingham super cell thunderstorm had a tornado warning on it continuously for over 300 miles. It hasn't been determined yet how long this tornado was more or less continuously on the ground, but I have seen references to a 200 mile long damage path. The Tri-State Tornado had a damage path of over 200 miles, and yet stands out there seemingly as this extreme outlier event, tracking across 3 states and definitely producing F5 damage across Illinois and Indiana. Most meterologists suspect it wasn't on the ground the entire 200+ mile distance, but it clearly was on the ground for most of this length. It was definitely an outlier event, but the question is how much of an outlier - is that a 100, 500, or 1,000 year event. If we do end up with something approaching a 200 mile damage path, this would really indicate that the Tri-State Tornado was perhaps more like a 100 year event, and creates the real possibility of a similar length storm at some point in the future.
Saturday, April 30, 2011
Sunday, March 20, 2011
Watching Economic Activity
A house is being built on the vacant lot behind our yard. As an economist we analyze GDP but don't often get to observe it being created.
The housing market I think is a challenge for free market economists. It is a market where reputation should be very important - houses are an experience good, and because of their durability it may be years before you see if a house was really poorly constructed. Houses are also high value items, and so a builder could make a relatively large profit by reducing quality. In a development of even 20 modestly upscale homes, shoddy construction could yield a fairly nice profit for a developer who could then fold their company and leave no asset trail for homeowners to pursue. And yet reputation does not seem to be very important in the market - we don't see homes labeled with brand names. How many homeowners know who built the house they own? There are some national builders now, but the market is extremely decentralized and localized. This seems to be strongly at odds with our theory of markets and the role of reputation.
The small role reputation plays in homebuilding puzzles me. I don't have a satisfactory answer. I discussed this with Randy Holcombe once and he pointed out the importance of owner maintenance. If an owner doesn't maintain the house, quality will deteriorate, but it would be hard for potential buyers or others in the market to know if poor initial construction or a lack of maintenance explains the dilapidated state. This may play a role, but it seems the same argument applies with cars and we see brand names and reputation play an important role there. Indeed, auto makers will tout the resale value of cars in ads. If maintenance was an issue, builders could design minimal maintenance homes, or offer extended maintenance bundled with the initial purchase to credibly demonstrate to subsequent buyers that the home has been maintained.
I suspect (and one day would like to try to demonstrate more formally) that the existence of public sector building codes plays an important role. Home buyers know that there are building codes, and thus that the local public sector is certifying quality. This I suspect results in a lulling effect among buyers - they don't worry about who built the house they want to buy because they figure it must have passed code inspection and be well built. But building code enforcement is quite lax in many areas, and thus the public sector promise of quality may not be very reassuring. And the existence of codes probably increases the marginal cost of assuring a higher quality of construction than offered in the local building code.
Carolina Homes is building the house on the lot behind us. I hope for the new owners that they are a high quality builder. We've had one hurricane and one tropical storm in the last 3 years in Deep South Texas, so poor construction can lead to problems.
The housing market I think is a challenge for free market economists. It is a market where reputation should be very important - houses are an experience good, and because of their durability it may be years before you see if a house was really poorly constructed. Houses are also high value items, and so a builder could make a relatively large profit by reducing quality. In a development of even 20 modestly upscale homes, shoddy construction could yield a fairly nice profit for a developer who could then fold their company and leave no asset trail for homeowners to pursue. And yet reputation does not seem to be very important in the market - we don't see homes labeled with brand names. How many homeowners know who built the house they own? There are some national builders now, but the market is extremely decentralized and localized. This seems to be strongly at odds with our theory of markets and the role of reputation.
The small role reputation plays in homebuilding puzzles me. I don't have a satisfactory answer. I discussed this with Randy Holcombe once and he pointed out the importance of owner maintenance. If an owner doesn't maintain the house, quality will deteriorate, but it would be hard for potential buyers or others in the market to know if poor initial construction or a lack of maintenance explains the dilapidated state. This may play a role, but it seems the same argument applies with cars and we see brand names and reputation play an important role there. Indeed, auto makers will tout the resale value of cars in ads. If maintenance was an issue, builders could design minimal maintenance homes, or offer extended maintenance bundled with the initial purchase to credibly demonstrate to subsequent buyers that the home has been maintained.
I suspect (and one day would like to try to demonstrate more formally) that the existence of public sector building codes plays an important role. Home buyers know that there are building codes, and thus that the local public sector is certifying quality. This I suspect results in a lulling effect among buyers - they don't worry about who built the house they want to buy because they figure it must have passed code inspection and be well built. But building code enforcement is quite lax in many areas, and thus the public sector promise of quality may not be very reassuring. And the existence of codes probably increases the marginal cost of assuring a higher quality of construction than offered in the local building code.
Carolina Homes is building the house on the lot behind us. I hope for the new owners that they are a high quality builder. We've had one hurricane and one tropical storm in the last 3 years in Deep South Texas, so poor construction can lead to problems.
One on One Volume 2
Natalie and I got ourselves Tony Horton's One on One Volume 2 dvds for Valentine's Day. There are some excellent workouts in there. My favorite is probably Cardio Confusion - Mason's Choice. I like the Hummingbird yoga workout as well, since this yoga is really more like a stretch routine than the other yoga workouts.
Subscribe to:
Posts (Atom)