Quotes from Steven D. Levitt

prohibir a los médicos llevar corbata, porque, como ha observado el Departamento de Salud del Reino Unido, «se lavan muy de vez en cuando», «no tienen ningún efecto beneficioso en la atención al paciente» y «se ha demostrado que están colonizadas por patógenos».

Daniel Kahneman has written: "[W]e can be blind to the obvious, and we are also blind to our blindness.

35 million fewer females than males in the population.

Por cada persona inteligente que se molesta en crear un esquema de incentivos, existe un ejército de gente, inteligente o no, que inevitablemente invertirá incluso más tiempo en tratar de burlarlos.

cuando existe una gran cantidad de gente dispuesta a realizar un trabajo y capaz de hacerlo, por lo general éste no está bien remunerado. Ése es uno de los cuatro factores significativos que determinan un salario. Los otros tres son los conocimientos especializados que requiere un trabajo, lo desagradable que sea y la demanda de servicios que satisface.

the gap steadily grows over the second and third grades.

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.

If almost all letters have stamps, then the benefit of checking each one with 100 percent accuracy is infinitesimal, so it makes sense to let some unstamped letters through.

51 percent of Indian men said that wife-beating is justified under certain circumstances; more surprisingly, 54 percent of women agreed—

Por razones que Auvert y otros científicos no comprenden del todo, se descubrió que la circuncisión reduce el riesgo de transmisión del VIH hasta en un 60 por ciento en los hombres heterosexuales.

Between 1995 and 2005, there were on average 60.3 worldwide shark attacks each year, with a high of 79 and a low of 46. There were on average 5.9 fatalities per year, with a high of 11 and a low of 3. In other words, the headlines during the summer of 2001 might just as easily have read "Shark Attacks About Average This Year." But that probably wouldn't have sold many magazines.

Look around the world and you'll find overwhelming evidence of the herd mentality at work.

There is nothing like the sheer power of numbers to scrub away layers of confusion and contradiction.

Just how are the black schools bad? Not, interestingly, in the ways that schools are traditionally measured. In terms of class size, teachers' education, and computer-to-student ratio, the schools attended by blacks and whites are similar. But the typical black student's school has a far higher rate of troublesome indicators, such as gang problems, nonstudents loitering in front of the school, and lack of PTA funding. These schools

Particular gift is the ability to ask such questions. For instance: If drug dealers make so much money, why do they still live with their mothers? Which is more dangerous, a gun or a swimming pool? What really caused crime rates to plunge during the past decade? Do real-estate agents have their clients' best interests at heart? Why do black parents give their children names that may hurt their career prospects? Do schoolteachers cheat to meet high-stakes testing.

A mountain of recent evidence suggests that teacher skill has less influence on a student's performance than a completely different set of factors: namely, how much kids have learned from their parents, how hard they work at home, and whether the parents have instilled an appetite for education.

A great deal of conventional wisdom is built on nothing more than a story that someone has been telling for so long—often out of self-interest—that it is treated like gospel.

If asked how we'd behave in a situation that pits a private benefit against the greater good, most of us won't admit to favoring the private benefit. But as history clearly shows, most people, whether because of nature or nurture, generally put their own interests ahead of others'. This doesn't make them bad people; it just makes them human.

When you're that engaged, you'll run circles around other people even if they are more naturally talented.

It's easy to let your biases—political, intellectual, or otherwise—color your view of the world. A growing body of research suggests that even the smartest people tend to seek out evidence that confirms what they already think, rather than new information that would give them a more robust view of reality.

asimetría de la información, un estado en el que en una transacción una de las partes posee mejor información que otra.

even the smartest people tend to seek out evidence that confirms what they already think, rather than new information that would give them a more robust view of reality.

For until you can admit what you don't yet know, it's virtually impossible to learn what you need to.

It isn't only that we know less than we pretend about the outside world; we don't even know ourselves all that well.