Freakonomics update

Dubner defends himself here. No word on the drunk driving advice, but he has some backstory on the interviews that he and Levitt did regarding global warming. It seems pretty clear that their approach to writing Freakonomics 2 was much different than the original book: the first Freakonomics was all about Levitt’s work, whereas the most prominent part of the sequel is a discussion of the ideas of others. As I noted yesterday, this creates a huge selection issue–how did they decide whom to interview?–which is much less present in the first book. I’m also still confused that Dubner describes global warming as “a very difficult problem to solve,” given that on his blog the other day he seemed to be endorsing the view that future trends are “virtually assuring us of about 30 years of global cooling.”

My guess is that Levitt/Dubner’s views on the topic are not completely coherent (by which I mean, not that Levitt and Dubner disagree with each other, but that between them they have a bunch of partly conflicting attitudes on the topic). As a political scientist, I’m the last person to criticize attitudes for being incoherent, and given that neither Levitt nor Dubner is an expert on climate change, it’s probably a good thing that their attitudes are fluid and not so easy to pin down. The difficulty comes when they feel the need to defend everything that they’ve written so far. Again, this is tougher to do here than in the Freakonomics 1 examples, partly because Levitt was much more of an expert on his own research than on others’ research, and partly, I suppose, because you’ll get a lot more flak in the major news media if you question global warming than if you write about the beneficial consequences of abortion.

P.S. But see the second blurb here!

P.P.S. In my previous entry, I asked why pissing off liberals seems so much fun, whereas pissing off conservatives seems earnest and boring. Jonathan Bernstein, Mark Liberman, John Quiggin, and Kieran Healy offer up their theories.

P.P.P.S. Phil Nugent points out (in an entry unrelated to Freakonomics in any of its forms) that, in the days of Lenny Bruce and Richard Pryor, pissing off conservatives was the way to be cool. Those dudes were serious and even earnest at times but not tame or boring. And when P. J. O’Rourke got his Republican Party Reptile thing going, back in the 80s, it was funny partly because it was new. Things have changed.

P.P.P.P.S. Regarding Levitt and Dubner’s apparent opposition to emissions reduction, Matthew Yglesias correctly points out that, contrarian as this might be, it’s a reinforcement of the status quo. But then he writes, “if you take up the side of the status quo and join forces with the politically and economically powerful, you don’t get to don the mask of the bold truth-teller willing to speak out against ingrained prejudice…” I see what he means, but on the other hand, Levitt and Dubner really are getting a lot of flak for their position. So, if their goal is to be taken seriously in general (and not just labeled as partisan pundits), they really have taken a bold risk, of the sort that they wouldn’t have taken, had they taken a more conventional line and discussed the economic costs and benefits of conservation (perhaps, for example, taking an “Everything you thought you knew was wrong” stance by discussing how we weren’t in such bad shape, because we could all cut our emissions without much difficulty were we to better understand the paradoxes recently unearthed by economists that explain how our actual well-being differs from our anticipation of same).

P.P.P.P.P.S. A review from Tim Harford, who finds the book to be entertaining and thought provoking. No discussion of Levitt and Dubner’s drunk driving advice, unfortunately. Interestingly, Harford evaluates the book as a good read and a conversation-starter rather than as a set of definitive pronouncements on the issues of the day. Perhaps Levitt is not taken as seriously in England as in the U.S., hence there’s less worry there about the impact of any overreaching he might do on issues ranging from abortion to climate change.

25 thoughts on “Freakonomics update

  1. Krugman makes a good point about Stewart and Colbert. But it's hard for me to believe this is about careerism on Levitt's part. I'm guessing that this whole thing is a career mistake for Levitt–at least, for the kind of career I imagine he'd like to continue having. And, remember, in Freakonomics 1, Levitt had no problem pissing off conservatives regarding abortion and guns. Most of his work on crime has a broadly liberal slant, I'd say. For Freakonomics 2, I think what happened is that Levitt got into some sloppy habits while blogging and this leaked into the new book. I imagine he's been much more careful in his academic work.

  2. Interesting note. You can search this blog for Heckman for further discussion of some of these issues. With regard to Levitt, let me just say that, yes, the abortion/crime paper seems to have gone to the edge of credibility, and I'm sure others of his papers have weak points too, but he's done a lot of solid work on important topics. It's not all about sumo wrestling.

  3. Then in late 2005, about a half year after "Freakonomics" came out, Boston Fed economists Christopher Foote and Christopher Goetz figured out why Levitt's abortion-cut-crime theory didn't match up with the actual crime rates: because he had messed up the programming.

    Of course, none of this affected his career as a celebrity. Once a celebrity, always a celebrity.

  4. Andrew:

    I'm reading between the lines on some your views about Levitt, but it seems to me you think he's more of an honest contrarian than he actually may be. His political/philosophical bias is presumably Libertarianism, not conservativism. Or at least that view would align with all of his positions ranging from abortion to climate change.

    This is precisely why I have such a hard time taking anything he does seriously–because all his research findings and opinions align so closely with this brand of Libertarian ideology. While, from a philosophical standpoint, I can sympathize with his ideology to some extent, the fervor with which he seems to adhere to it in his supposedly objective research is, well, difficult for me to see as genuine.

    In other words, he's not a critical skeptic trying hard to see all sides. He's simply skeptical of anything that does not conform to Libertarianism.

    Also, some of his work has been shown to be quite sloppy.

  5. Mike:

    I wouldn't be surprised if Levitt has a strong political ideology, but I don't see why it should pop out in this research. To take the examples at hand, what are the connections between libertarianism on one hand, and drunk driving and climate change on the other?

    Any connections seem to me to be pretty indirect. Something like this: there are public service announcements on the radio telling people not to drive drunk. If you're a libertarian, you don't like the nanny state, so you don't like "nudges" or even public service announcements, so you want to say that drunk driving's not so bad.

    Or, Al Gore wants to institute carbon taxes. As a libertarian, you don't like taxes because the proceeds can be used to expand government, thus reducing freedom and also crowding out private investment, etc etc. Big-government types have a track record of setting up boogeymen to scare people into coughing up their taxes. In the old days the boogeymen were Nazis and communists, now it's global warming. Whatever it is, if people are using it as a way to raise taxes, I don't trust it. Follow the money.

    OK, so both the above arguments have a sort of coherence, but they're indirect bank-shot sorts of reasoning, and I don't think it would take much for the arguments to go the other way. For example, as a libertarian, I don't want drunk drivers out on the road killing people who didn't consent to it. Or, as a libertarian, I don't think big rent-seeking corporations should be allowed to pollute without paying the consequences. Those arguments work too, no?

  6. Steve:

    Maybe Freakonomics 1 wasn't sunk by the abortion/crime criticisms because the kind of people who review books don't mind hearing good things about abortion, or maybe just because that first book was a new thing. Nowadays, Levitt and Dubner are yesterday's Beaujolais and it's more satisfying for people to take them on.

    Or maybe it's just that Freakonomics 1 had lots of good stuff in it–the crime stuff was the biggest part, but it wasn't the only thing. And, don't forget, Levitt's done lots of resarch on crime and related public policy issues. Say what you want about his overreaching on the abortion example, he's certainly an expert in the general area. There's a lot to ponder in the original Freakonomics.

    In contrast, Freakonomics 2 has global warming and what? Advice to drive drunk? A pretty technical criticism of some research in experimental psychology? An interview with a hooker??? Again, I haven't seen the book–that's of course why my blogging here represent the purest essence of book reviewing–but it sounds like it really stands or falls on its treatment of global warming. So they appear to be stuck with front-line defense on this. The retreat-into-the-Urals-and-wait-till-the-attackers-exhaust-themselves strategy won't do the trick.

  7. I reread the posted chapter about global warming and I still think it's a mediocre magazine article – maybe GQ quality, not New Yorker – but what really leapt out at me is the small part about the low probability of catastrophe. The odds – over 5% – are almost tossed off as a "Don't worry about that" but we've just lived through a disaster caused by ignoring the high consequence / even lower probability tail risk of certain financial models. I feel silly even writing this but a 1% risk of a catastrophe can be huge – like a 1% risk the planet blows up – and I would be ridiculously careful if someone told me I have a 5 or 10% risk of losing my legs.

  8. As a note on the comment above, I just ran across an email from Levitt (to Yoram Bauman, I think) in which he says that if the risk were 5% then yikes and that he meant the 5% is an outlier. I didn't read the chapter that way but in any event my point stands.

  9. Levitt can be viewed as a more extreme case of something that affects not only some areas of economics but also lots of the political science research: some (most?) people basically care about exciting stories and very little about good data analysis. Maybe they are just bored to get the numbers right. They prefer something entertaining over dense and reliable analysis. Good stores always make a strong cases in these professions (just think about the quality of the data analysis of most of what is published in the field of comparative politics.). On the other hand, my (vague) impression is that fields like biostats, demography and public health is much more about data analysis than aabout make stories.

  10. Just wanted to throw in my theory about why it is no longer fun to mock republicans. It is just that the reality of the contemporary republican party has grown so preposterous, no comedian can really do better than just to point out their actual opinions, positions and actions. I don't know what is going on with the modern republicans, but they seem to be un-shameable.

  11. There's no contradiction between thinking that (1) we are in for a spell of cooling for the next few decades, and that (2) the long-term trend is for a lot of warming.

  12. Phil: True, this post by Dubner is indeed consistent with the theory that the Earth will get cooler for 30 years and then it will heat up again. But, after reading that post and then reading their next posts on the topic (Levitt saying "we believe that rising global temperatures are a man-made phenomenon and that global warming is an important issue to solve" and Dubner saying "if global warming gets worse…"), I think it's fair to describe their position as incoherent. On one hand, they're sympathetic to the argument that conditions are "virtually assuring us of about 30 years of global cooling," on the other hand, they're seriously worried about what to do if global warming gets worse, and on the third hand they treat "rising global temperatures" as an unquestioned fact. There is perhaps a consistent story involving "rising global temperatures" now (in the continuing present tense), a virtually assured decline for the next 30 years, followed by, I suppose, a virtually assured even sharper rise around 2040 or so, but it's hard for me to believe they're selling that complicated a story. The much more plausible explanation to me (again, though, I haven't read the book) is a bit of incoherence. And, again, incoherence is fine here: Levitt and Dubner are not climate experts so coherence from them on this issue is neither required nor perhaps even desired. But I think it is putting them in some awkward positions as they try to piece together a position at this point. Dubner in particular seems torn between (a) an understandable desire to defend himself of charges of (mild) journalistic malpractice, and (b) a sympathy for the poke-in-the-eye-of-the-experts-style of politically-incorrect research. My impression of Levitt (based on no more than the evidence I see here) is that he would feel safest falling back onto the conclusions of academic experts, but as this particular topic is far from his expertise in economics, he doesn't really know whom to trust. Put it all together and you get a mess.

  13. Andrew says:

    "And, don't forget, Levitt's done lots of resarch on crime and related public policy issues."

    True, but that came after his abortion-cut-crime theory was made public in 1999 as he tried to defend it.

    Here's the inside story, which I think is useful because it shows the perils of intellectual imperialism by economists.

    In December 1998, Levitt and John J. Donohue completed a paper arguing the legalizing abortion cut crime. The empirical basis was a comparison of crime rates in 1985, when most criminals had been born before abortion was legalized (in New York and California in 1970 and in the rest of the country in January 1973) versus the lower crime rates of 1997.

    They took their paper around and presented it at symposiums at economics departments of prestigious universities. Apparently, they got warm receptions, and nobody impressed upon them that they ought to look at the years between 1985 and 1997: i.e., the Crack Wars.

    The Chicago Tribune heard about it and made it a front page story in August 1999.

    My friend Greg Cochran pointed out to me that if you look at the homicide rate by year for all the years in between 1985 and 1997, Levitt's theory doesn't look valid. I then looked at the homicide rate by age group, and got absolutely opposite results.

    I then arranged to debate Levitt in in late August 1999. As I pointed out in Slate:

    "The problem with your abortion/reduced-crime theory is not that it encourages abortion or eugenic reasoning or whatever, but that it's largely untrue. Your biggest methodological mistake was to focus on the crime rates only in 1985 and 1997. Thus, you missed the 800-pound gorilla of crime trends: the rise and fall of the crack epidemic during the intervening years.

    "Here's the acid test. Your logic implies that the babies who managed to get born in the '70s should have grown up to be especially law-abiding teens in the early '90s. Did they?

    "Not exactly. In reality, they went on the worst youth murder spree in American history. According to FBI statistics, the murder rate for 1993's crop of 14- to 17-year-olds (who were born in the high-abortion years of 1975 to 1979) was a horrifying 3.6 times that of the kids who were 14 to 17 years old in 1984 (who were born in the pre-legalization years of 1966 to 1970). In dramatic contrast, over the same time span the murder rate for those 25 and over (all born before legalization) dropped 6 percent.

    "Your model would also predict that the recent decline in crime should have shown up first among the youngest, but the opposite was true. The murder rate for 35- to 49-year-olds has been falling since the early '80s, and for 25- to 34-year-olds since 1991, but the two most homicidal years for 14- to 17-year-olds were 1993 and 1994. …

    "So, let's look at just black males born in 1975 to 1979. Since their mothers were having abortions at three times the white rate, that should have driven down their youth murder rate. Instead, from 1984 to 1993 the black male youth homicide rate grew an apocalyptic 5.1 times. This black juvenile rate also grew relative to the white juvenile murder rate, from five times worse in 1984 to 11 times worse in 1993."

    Levitt's response was, in effect, that, well sure, his theory looks dubious if you test it using simple numbers at the national level, but it you use really complicated statistics on a state-by-state basis, then he's golden.

    Finally, six years later, Foote and Goetz of the Boston Fed showed why Levitt's state-by-state analysis didn't match up with my national analysis: Levitt had made technical programming errors.

    But by then, Levitt and Dubner were already in business with the New York Times, so the NYT never mentioned this professional humiliation of their star blogger. (In contrast, the Wall Street Journal and The Economist gave Foote and Goetz's paper some publicity.)

  14. I think Yoram Bauman got it rightest:

    In my words (echoing Andrew's here): Dubner and Levitt simply blew it. They wrote a terrible chapter, far below their usual standards, popular or professional. Or to say it another way, they didn't bring to that chapter the high professional standards that they exhibit and expect in academic work.

    I'll be interested to see if they'll simply admit it. It strikes me that such an admission–even in our admission-wary society–could give a big boost to their status and reputation, both popular and professional.


  15. Everything I've seen is consistent with Levitt and Dubner thinking that we are in a short-term cooling cycle (that started four or five years ago) superimposed on a disastrous long-term warming trend that is attributable to greenhouse gas emissions. The quotes you give are entirely consistent with that view, which I do not think is a "complicated" story, as you put it.

    I don't think that story is correct, mind you — I think anthropogenic forcing is strong enough that the next twenty years are very likely to be warmer on average than the last twenty years, and I would welcome an opportunity to place a wager on that — but I think it's unfair to characterize their position as "incoherent" or "probably incoherent" based only on the available information. Dare I suggest that the best way to evaluate the position they take in the book is to read the book? But of course, that's just what they want you to do!

  16. Phil: I was thinking a bit more about your theory (that Levitt and Dubner consistently believe that the earth is in for another 20 years of cooling, to be followed by rapid warming), and I don't think so.

    Here's why. If Levitt and Dubner really thought the above, then it seems to me that:

    (a) When blogging about the 20-future-years-of-cooling, Dubner would've written something like, "But that doesn't mean we can relax. After about 20 years, some serious global warming is expected to kick in, for real."

    (b) When blogging about how "rising global temperatures are a man-made phenomenon and that global warming is an important issue to solve," Levitt would've written something like, "But don't forget that the earth is expected to get cooler for the next 20 years. We don't anticipate the real problems to be coming for another couple decades."

    But Levitt and Dubner didn't ever put these ideas together, which makes me think that they they're really just grabbing different things that they've heard and throwing them out there.

  17. I've heard of people who believe in anthropogenic global warming and I've heard of people who believe in global cooling (mainly, I think, as a reaction to other people believing in AGW), but is global-cooling-followed-by-global-warming really A Thing? Have I somehow managed to miss out on this?

    If not and that's what they really believe, it would seem more damning to me than if they were simple denialists. Going into a field you're not an expert in and concocting an entirely new theory that no one else supports seems like the height of arrogance.

  18. Andrew: "…" I see what he means, but on the other hand, Levitt and Dubner really are getting a lot of flak for their position." [so therefore the 'support the mainstream is contrarian]

    In terms of more criticism, the first Freaknomics book came out under the radar. Nobody knew to look out for it, so it got widespread reading before anybody could criticize it. In this case (a) people knew about L&D beforehand, and that one chapter got pre-published. It was both seen ahead of time, and seen by people who knew the science. And L&D made elementary errors (deliberately, IMHO) in distorting the comments of people they interviewed, which added both a personal aspect and the aspect of simply honesty.

    Second, it's pretty frickin' clear that they're bullsh*tting. When called upon it, their response was more bullsh*t. This has escalated the matter.

    Phil (I can't quote the relevant phrase, due to IE being a PITA): For Levitt to think that we're in a short-term cooling trend means that he can't read a chart. See the chart at:… for an example (I can't quickly find one which shows the last few decades better).

    The last decade was the hottest on record, the second hottest was the 1990's, the third-hottest was the 1980's, and so one. L&D, and everybody who plays the 'cooling trend' card, is exploiting what is clearly a blip in 1998 – one explained by the El Nino that year, which IIRC is considered to be the strongest on record.

    Now, I'd bet that most people who play that card simply are repeating what others said, and most of the rest are people who look at a chart and can't read it well (at least, when the chart says what they don't like), but a Chicago econ professor doesn't have that excuse. In addition, they allegedly talked with climatologists, and should have known that even if Levitt can't read a graph.

  19. Anon: Yeah, cooling-now-with-warming-later really is a "thing". A few years ago, when the "meme" meme was going around, we would have called it a meme. Here is a recent BBC News article that says "To confuse the issue even further, last month Mojib Latif, a member of the IPCC (Intergovernmental Panel on Climate Change) says that we may indeed be in a period of cooling worldwide temperatures that could last another 10-20 years…But he makes it clear that he has not become a sceptic; he believes that this cooling will be temporary, before the overwhelming force of man-made global warming reasserts itself."

    So, yeah, there is chatter on the Intertubes (and elsewhere) in which people with various degrees of credibility discuss the possibility that natural variability is currently in a cooling cycle, while anthropogenic CO2 is pushing us strongly towards warming. At least at the moment, most climate scientists don't see any reason to believe this, mostly because the CO2 effects are so large at this point. But everyone agrees with the basic principle that there are global temperature fluctuations at many temporal scales, so you don't expect to see a uniform increase, and there can be consecutive years of cooling.

  20. The BBC exaggerated Latif's position. Latif's WWC-3 presentation gave a hypothetical scenario, with synthetic data, demonstrating how decadal cooling can occur under natural variability. This wasn't an actual prediction, it was just random noise superimposed on a specified trend, selected to give an example of short-term cooling. That part of his talk was motivating the need for decadal prediction by showing how natural variability can obscure long term trends. It wasn't actually predicting anything.

    As it happens, Latif was a coauthor on the Keenlyside decadal prediction paper, which does make a prediction. The prediction there is of reduced warming, not cooling, and Latif has stated that he doesn't trust it past 2015 (let alone 2 decades into the future).

    I don't know where the BBC got their "we could receive 20 years of cooling" from. Latif's plot was a noise realization intentionally chosen to show cooling. Draw another realization and they could equally well have said "we could receive 20 years of accelerated warming". Latif himself never said that he expected any cooling.

    An accurate statement of Latif's position is that he expects particularly slow warming over the next 5-6 years, due to natural variability in the ocean state.

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