Great Performance !

It can’t, really—except in one special case. The key is to measure a candidate against… himself. That is, Candidate A today is likely to be similar to Candidate A two or four years hence. The same could be said for Candidate B. If only Candidate A ran against Candidate B in two consecutive elections but in each case spent different amounts of money. Then, with the candidates’ appeal more or less constant, we could measure the money’s impact. Read the rest of this entry »

Now, returning to the issue of campaign spending: in order to figure out the relationship between money and elections, it helps to consider the incentives at play in campaign finance. Let’s say you are the kind of person who might contribute $1,000 to a candidate. Chances are you’ll give the money in one of two situations: a close race, in which you think the money will influence the outcome; or a campaign in which one candidate is a sure winner and you would like to bask in reflected glory or receive some future in-kind Read the rest of this entry »

It might seem logical to think so, much as it might have seemed logical that a booming 1990s economy helped reduce crime. But just because two things are correlated does not mean that one causes the other. A correlation simply means that a relationship exists between two factors—let’s call them X and Y—but it tells you nothing about the direction of that relationship. It’s possible that X causes Y; it’s also possible that Y causes X; and it may be that X and Y are both being caused by some other factor, Z. Read the rest of this entry »

There’s one way to find out: measure the difference between the sales data for houses that belong to real-estate agents themselves and the houses they sold on behalf of clients. Using the data from the sales of those 100,000 Chicago homes, and controlling for any number of variables—location, age and quality of the house, aesthetics, and so on—it turns out that a real-estate agent keeps her own home on the market an average of ten days longer and sells it for an extra 3-plus percent, or $10,000 on a $300,000 house. Read the rest of this entry »

Before plunging into the data, it helps to ask a question: what is the real-estate agent’s incentive when she is selling her own home? Simple: to make the best deal possible. Presumably this is also your incentive when you are selling your home. And so your incentive and the real-estate agent’s incentive would seem to be nicely aligned. Her commission, after all, is based on the sale price. Read the rest of this entry »

Right?

It would be lovely to think so. But experts are human, and humans respond to incentives. How any given expert treats you, therefore, will depend on how that expert’s incentives are set up. Sometimes his incentives may work in your favor. For instance: a study of California auto mechanics found they often passed up a small repair bill by letting failing cars pass emissions inspections—the reason being that lenient mechanics ar e rewarded with repeat business. But in a different case, an expert’s incentives may work against you. In a medical study, it turned out that obstetricians in areas with declining birth rates are Read the rest of this entry »

It is the quintessential blend of commerce and camaraderie: you hire a real-estate agent to sell your home.

She sizes up its charms, snaps some pictures, sets the price, writes a seductive ad, shows the house aggressively, negotiates the offers, and sees the deal through to its end. Sure, it’s a lot of work, but she’s getting a nice cut. On the sale of a $300,000 house, a typical 6 percent agent fee yields $18,000. Eighteen thousand dollars, you say to yourself: that’s a lot of money. But you also tell yourself that you never could have sold the house for $300,000 on your own. The agent knew how to—what’s that phrase she used?—“maximize the house’s value.” She got you top dollar, right? Read the rest of this entry »

So how did Roe v. Wade help trigger, a generation later, the greatest crime drop in recorded history?

As far as crime is concerned, it turns out that not all children are born equal. Not even close. Decades of studies have shown that a child born into an adverse family environment is far more likely than other children to become a criminal. And the millions of women most likely to have an abortion in the wake of Roe v. Wade—poor, unmarried, and teenage mothers for whom illegal abortions had been too expensive or too hard to get—were often models of adversity. They were the very women whose children, if born, would Read the rest of this entry »

These theories were not only logical; they were also encouraging, for they attributed the crime drop to specific and recent human initiatives. If it was gun control and clever police strategies and better-paying jobs that quelled crime—well then, the power to stop criminals had been within our reach all along. As it would be the next time, God forbid, that crime got so bad.

These theories made their way, seemingly without question, from the experts’ mouths to journalists’ ears to the public’s mind. In short course, they became conventional wisdom. Read the rest of this entry »

Other criminologists, political scientists, and similarly learned forecasters laid out the same horrible future, as did President Clinton. “We know we’ve got about six years to turn this juvenile crime thing around,” Clinton said, “or our country is going to be living with chaos. And my successors will not be giving speeches about the wonderful opportunities of the global economy; they’ll be trying to keep body and soul together for people on the streets of these cities.” The smart money was plainly on the criminals. Read the rest of this entry »