Sendhil Mullainathan

Time can be dissected easily: an hour can be cut up in many ways. Fifteen minutes on this memo, a five-minute walk to another meeting, 30 minutes at that meeting and then 10 minutes debriefing. Oh, and maybe a quick phone call on the walk to that meeting. The busy are expert at dissection: that's how they make it all fit.

Faced with a time shortage, we squeeze tasks into the nooks and crannies of our calendar, leaving less and less time to switch between them. As a result, we become less and less productive exactly when we need to be most productive.

If you send out one coupon with a deadline of a week and another that must be used within the next month, you end up having more redemptions with the one week deadline. It's really amazing. With the month deadline you have four times as much time, but people tend to say they'll use it in a few weeks' time and then they don't do it.

Web searching and cellphone use both flourish in the wee hours. Before the dawn of the web, I would stay up watching television. But there is something soporific about television: I would often nod off. Not so when I'm online. As technologies expand, these problems may only worsen.

You and I can be busy, and we take a vacation from work. You can't take a break from being poor. You can't say, 'Hey I've had enough of worrying about money, I'm just going to be rich for a couple of weeks until I've recovered.'

It is safe to say that when people are short on cash, they might be less productive at work, be worse parents, and have less self-control.

The problem with data is that it says a lot, but it also says nothing. 'Big data' is terrific, but it's usually thin. To understand why something is happening, we have to engage in both forensics and guess work.

Eat better or work out more, and you'll see the benefits weeks, months or years down the road. Sleep more, and you'll see the benefits tomorrow.

There's a popular image of people who don't save for the future as lacking in self-control. But the reason saving is so hard has less to do with self-control and more to do with a scarcity of attention.

The scarcity trap captures this notion we see again and again in many domains. When people have very little, they undertake behaviors that maintain or reinforce their future disadvantage. If you have very little, you often behave in such a way so that you'll have little in the future.