Quotes from Steven D. Levitt

When was the last time you sat for an hour of pure, unadulterated thinking?

The modern world demands that we all think a bit more productively, more creatively, more rationally; that we think from a different angle, with a different set of muscles, with a different set of expectations; that we think with neither fear nor favor, with neither blind optimism nor sour skepticism. That we think like—ahem—a Freak.

But guns are not the whole story. In Switzerland, every adult male is issued an assault rifle for militia duty and is allowed to keep the gun at home. On a per capita basis, Switzerland has more firearms than just about any other country, and yet it is one of the safest places in the world. In other words, guns do not cause crime.

Think about all the time, brainpower, and social or political capital you continued to spend on some commitment only because you didn't like the idea of quitting.

It has long been said that the three hardest words to say in the English language are I love you. We heartily disagree! For most people, it is much harder to say I don't know. That's a shame, for until you can admit what you don't yet know, it's virtually impossible to learn what you need to.

Here's a guess: anybody who bothers to change his name in the name of economic success is—like the high-school freshmen in Chicago who entered the school-choice lottery—at least highly motivated, and motivation is probably a stronger indicator of success than, well, a name.

The impulse to investigate can only be set free if you stop pretending to know answers that you don't. Because the incentives to pretend are so strong, this may require some bravery on your part.

That is a lethal combination—cocky plus wrong—especially when a more prudent option exists: simply admit that the future is far less knowable than you think.

The next time you encounter such a barrier, imposed by people who lack your imagination and drive and creativity, think hard about ignoring it. Solving a problem is hard enough; it gets that much harder if you've decided beforehand it can't be done.

Roland G. Fryer Jr., while discussing his names research on a radio show, took a call from a black woman who was upset with the name just given to her baby niece. It was pronounced shuh-TEED but was in fact spelled "Shithead."*

Correlation does not equal causality. When two things travel together, it is tempting to assume that one causes the other. Married people, for instance, are demonstrably happier than single people; does this mean that marriage causes happiness? Not necessarily. The data suggest that happy people are more likely to get married in the first place. As one researcher memorably put it, "If you're grumpy, who the hell wants to marry you?

A moral compass can convince you that all the answers are obvious (even when they're not); that there is a bright line between right and wrong (when often there isn't); and, worst, that you are certain you already know everything you need to know about a subject so you stop trying to learn more.

Pay attention to how people respond; if their response surprises or frustrates you, learn from it and try something different.

Human beings aren't the most candid animals on the planet. We'll often say one thing and do another—or, more precisely, we'll say what we think other people want to hear and then, in private, do what we want.

It also means that the pain of negative feedback will for most people trump the pleasure from positive feedback.

We'd like to bury the idea that there's a right way and a wrong way, a smart way and a foolish way, a red way and a blue way. The modern world demands that we all think a bit more productively, more creatively, more rationally; that we think from a different angle, with a different set of muscles, with a different set of expectations; that we think with neither fear nor favor, with neither blind optimism nor sour skepticism. That we think like—ahem—a Freak.

A person who is lying or cheating will often respond to an incentive differently than an honest person.

Name-calling will make you an enemy, not an ally, and if that is your objective, then persuasion is probably not what you were after in the first place.

The economic approach is both broader and simpler than that. It relies on data, rather than hunch or ideology, to understand how the world works, to learn how incentives succeed (or fail), how resources get allocated, and what sort of obstacles prevent people from getting those resources, whether they are concrete (like food and transportation) or more aspirational (like education and love).

just because you're great at something doesn't mean you're good at everything. Unfortunately, this fact is routinely ignored by those who engage in—take a deep breath—ultracrepidarianism, or "the habit of giving opinions and advice on matters outside of one's knowledge or competence.

conventional wisdom dies hard.

El prestigio parece ejercer una especie de magia que da salud —dice Andrew Oswald, uno de los autores del estudio—. Al parecer, subir a ese estrado de Estocolmo añade unos dos años a la vida de un científico».

para cambiar el mundo, primero hay que comprenderlo.

The future is far less knowable than you think.