Sendhil Mullainathan

It's 2014, and women are still paid less than men. Does this suggest that a gender pay gap is an unfortunately permanent fixture? Will it still be with us in 50 years? I would predict yes. But by that point, it will be men who will be earning less than women.

As a researcher, every once in a while you encounter something a little disconcerting. And this is something that changes your understanding of the world around you, and teaches you that you're very wrong about something that you really believed firmly in.

January is always a good month for behavioral economics: Few things illustrate self-control as vividly as New Year's resolutions. February is even better, though, because it lets us study why so many of those resolutions are broken.

Even when a man and a woman perform equally well in a task - say, solving math problems - men are more willing to enter competitions based on that task. Men also show less risk aversion.

One cost, for the lonely: If you want to be interesting, the one thing you shouldn't do is really focus on the fact that 'I want this person to like me.' That's going to make you very uninteresting. But the lonely, they just can't help but focus on that.

Maybe poverty is a special case of something else. That something else is 'scarcity,' and anyone who has the experience of 'having very little' experiences the same psychology.

If you have urgent current expenses to cover, then future priorities like college and retirement fall off your radar because they are simply less pressing. Scarcity of attention prevents us from seeing what's really important. The psychology of scarcity engrosses us in only our present needs.

Economists specialize in pointing out unpleasant trade-offs - a skill that is on full display in the health care debate. We want patients to receive the best care available. We also want consumers to pay less. And we don't want to bankrupt the government or private insurers. Something must give.

Organizations talk about spending their lives firefighting - dealing with the next problem without having the bandwidth to deal with what is down the pipeline. I think most of the poor have that problem.

We should try to ensure that everyone has a fair opportunity to find a great life. It's a quest that will require political will and ingenious policies. President Obama's proposed expansion of the earned-income tax credit goes in this direction, but we need more.

Task switching is hard because we do not control what is on our mind. Despite our efforts, the original task continues to occupy our mental bandwidth. Although we can control where our time goes, we cannot fully control how our bandwidth is allocated.

I worry about growing income inequality. But I worry even more that the discussion is too narrowly focused. I worry that our outrage at the top 1 percent is distracting us from the problem that we should really care about: how to create opportunities and ensure a reasonable standard of living for the bottom 20 percent.