Because macroeconomists have messed it up for every one else , says Noah Smith at The Week:
To put it mildly, economists have fallen out of favor with the public since 2008. First they failed to predict the crisis, or even to acknowledge that such crises were possible. Then they failed to agree on a solution to the recession, leaving us floundering. No wonder there has been a steady flow of anti-economics articles (for example, this, this, and this). The rakes and pitchforks are out, and the mob is ready to assault the mansion of these social-science Frankensteins.
But before you start throwing the torches, there is something I must tell you: The people you are mad at are only a small fraction of the economics profession. When people in the media say “economists,” what they usually mean is “macroeconomists.” Macroeconomists are the economists whose job is to study business cycles — booms and busts, unemployment, etc. “Macro,” as we know it in the profession, is sort of the glamor division of econ — everyone wants to know whether the economy is going to do well or poorly. Macro was what Keynes wrote about, as did Milton Friedman and Friedrich Hayek.
The problem is that it’s hard to get any usable results from macroeconomics. You can’t put the macroeconomy in a laboratory and test it. You can’t go back and run history again. You can try to compare different countries, but there are so many differences that it’s hard to know which one matters. Because it’s so hard to test out their theories, macroeconomists usually end up arguing back and forth and never reaching agreement.
Meanwhile, there are many other branches of economics, doing many vital things.
What are those vital things? Some economists find ways to improve social policies that help the unemployed, disabled, and other vulnerable populations. Others design auctions for Google. Some evaluate development polices for Kenya. Others help start-ups. And on and on. Love it or hate it, their work should be judged on its own merits, not lumped in with the very different world of macroeconomics.
A much-deserved Nobel prize today for Lloyd Shapley and Alvin Roth for their theoretical and practical work on designing markets. In particular, matching markets where you don’t have prices to help you.
The Royal Swedish Academy of Science released a very readable account of their contributions here. Here’s the introduction:
This year’s Prize to Lloyd Shapley and Alvin Roth extends from abstract theory developed in the 1960s, over empirical work in the 1980s, to ongoing efforts to find practical solutions to real-world problems. Examples include the assignment of new doctors to hospitals, students to schools, and human organs for transplant to recipients. Lloyd Shapley made the early theoretical contributions, which were unexpectedly adopted two decades later when Alvin Roth investigated the market for U.S. doctors. His findings generated further analytical developments, as well as practical design of market institutions.
Traditional economic analysis studies markets where prices adjust so that supply equals demand. Both theory and practice show that markets function well in many cases. But in some situations, the standard market mechanism encounters problems, and there are cases where prices cannot be used at all to allocate resources. For example, many schools and universities are prevented from charging tuition fees and, in the case of human organs for transplants, monetary payments are ruled out on ethical grounds. Yet, in these – and many other – cases, an allocation has to be made. How do such processes actually work, and when is the outcome efficient?
Along with his colleague David Gale, Shapley provided theoretical answers to these questions based on the idea of finding stable allocations (i.e., allocations in which no one would later have an incentive to change their mind). Roth then studied how those answers apply in real markets, e.g., designing algorithms to match doctors to hospitals.
Roth also blogs at the aptly-named Market Design. What did he write about yesterday? How Nobel Prizes correlate with chocolate consumption.
P.S. For a moving example of how well-designed matching markets improve human lives, see this post about kidney exchanges.
Over at Managerial Econ, Luke Froeb highlights a nice example of the winner’s curse. Like Google, Yahoo uses automated auctions to sell ads. One wrinkle is that some advertisers prefer to pay for impressions, some prefer to pay for clicks, and some prefer to pay only for resulting sales. Yahoo thus needs some mechanism to put these different payment approaches on a comparable footing:
To choose the highest-valued bidder, Yahoo develops predictors of how many clicks and sales result from each impression. For example, if one click occurs for every ten impressions, an advertiser would have to bid more than 10 times as high for a click as for an impression in order to win the auction.
Yahoo was very proud of its predictors, but was puzzled that they systematically over-predicted the actual number of clicks or sales after the auctions closed.
This is the winner’s curse in action. As auction guru (and Yahoo VP) Preston McAfee explains in the paper Luke cites:
In a standard auction context, the winner’s curse states that the bidder who over-estimates the value of an item is more likely to win the bidding, and thus that the winner will typically be a bidder who over-estimated the value of the item, even if every bidder estimates in an unbiased fashion. The winner’s curse arises because the auction selects in a biased manner, favoring high estimates. In the advertising setting, however, it is not the bidders who are over-estimating the value. Instead, the auction will tend to favor the bidder whose click probability is overestimated, even if the click probability was estimated in an unbiased fashion.
McAfee then goes on to explain how Yahoo overcame this self-inflicted winner’s curse, and other strategies to improve auction performance.
Yesterday the Treasury auctioned off its TARP warrants in Capital One. Treasury sold the warrants for $11.75 a piece, well above its $7.50 reserve price, but below some private estimates of $19.00 or more. I wouldn’t have gone as high as $19.00 myself, but I would have ended up a winner in the auction if I had found a broker with access. Oh well, maybe I can pick some up when they start trading on the NYSE (ticker COF WS) in the next week or two.
Disclosure: I have no position in any Capital One securities.
Thursday is a nice milestone in TARP’s history: with the help of Deutsche Bank, Treasury is auctioning off the warrants it received when it invested in Capital One. The company has already paid off the preferred stock that the government purchased last fall, and will now be free from TARP oversight once the warrants are in private hands. Or, perhaps, in its own hands. Although Capital One declined to purchase the warrants from Treasury at a negotiated price (as had other firms that repaid the government’s TARP investments), it can still bid in the auction.
A few months ago, I pointed out many benefits from auctioning the warrants rather than selling them back to the companies at negotiated prices. To my mind, the biggest benefits are transparency and the fairness of market pricing. Everyone—including, at least in principle, small investors—can bid in the auction.
If you are interested, here’s the prospectus, which includes (pp. S-15 to S-16) a list of participating brokers. I don’t see my broker on the list, which is disappointing, but maybe others will be luckier.
For a nice discussion of the auction mechanism (a modified Dutch auction in which all winning bidders pay the market-clearing price, very similar to the method used to sell Treasury bonds) and some estimates of the warrant values, see this Seeking Alpha piece by Linus Wilson.
Disclosure: I have no position in Capital One and, apparently, no way to bid on the warrants. If I find a way, I might do it for fun.
Am I the only one who feels unfulfilled by the standard distinction between positive and normative economics?
I am gearing up to return to the classroom next week, to teach microeconomics to incoming masters students at the Georgetown Public Policy Institute. Anyone who’s experienced the first day of micro class knows what’s coming. After introducing myself and talking about the wonders of economics (which is, indeed, fun, useful, and enlightening), I will launch into the great positive vs. normative distinction.
- Positive is the science side of economics: understanding and predicting the behavior of individuals, firms, markets, economies, etc. In short, the part of economics in which we try to be physicists (or, sometimes, biologists).
- Normative is the side of economics where we make value judgments, identifying policies as good or bad. In short, the part of economics in which we try to be philosopher-kings.
Both styles of economics are important, particularly in a public policy program. And drawing a careful distinction is vital, not least because of the many people in Washington (both economists and non-economists) who try to dress up their value judgments as science.
I have one problem with this distinction, however: it overlooks a great deal of what economists actually do.
Continue reading “Positive, Normative, and … ?”
On Friday, the House of Representatives passed its climate change bill by a slim margin. The bill’s key feature is a cap-and-trade system for greenhouse gases. That system would set national emission limits and would require affected emitters to own permits (called allowances) to cover their emissions.
The number one thing you should know about this bill is that the allowances are worth big money: almost $1 trillion over the next decade, according to the Congressional Budget Office, and more in subsequent decades.
There are many good things the government could do with that kind of money. Perhaps reduce out-of-control deficits? Or pay for expanding health coverage? Or maybe, as many economists have suggested, reduce payroll taxes and corporate income taxes to offset the macroeconomic costs of limiting greenhouse gases?
Choosing among those options would be a worthy policy debate. Except for one thing: the House bill would give away most of the allowances for free. And it spends virtually all the revenue that comes from allowance auctions.
As a result, the budget hawks, health expanders, and pro-growth forces have only crumbs to bargain over. From a budgeteer’s perspective, the House bill is a disaster.
The following table illustrates how much revenue the bill would raise and compares it to the alternative of auctioning all the allowances:
Continue reading “Big Money in Cap-and-Trade”