What we can’t spend

Some things, like money, time, and effort, are scarce resources that need careful budgeting to be used optimally. Some of those, like effort and attention, can return stronger after resting from difficult use, as if they’ve been built up like a muscle through exercise, which makes the calculus of optimizing how much and when to … More What we can’t spend

What we spend

Ever since I learned that the Dutch word for “to spend” (besteden) is used not just with time and money, as in English, but also with attention, I’ve started to wonder what else we have that we spend, and could be spending more wisely. Here is an incomplete list I’ve compiled: Money (of course). Time. … More What we spend

If you have a question, someone else probably has it too…

I often tell my students, “When you have a question, ask, because you’re probably not the only one who’s wondering.” I heard the same thing when I was a student, but I still felt embarrassed to ask. What if I really was the only one? Wouldn’t I be slowing down class to ask? If no … More If you have a question, someone else probably has it too…

Spontaneous Inequality

A fun problem making the mathematical rounds: if you give everybody some number of dollars (say you give 45 people $45 each), and at every tick of the clock everyone with money chooses one random person $1, how will the money eventually end up distributed? You might think it’ll stay approximately equal—”approximately” only because of … More Spontaneous Inequality

When is a mixture better than a middle?

We often optimize by looking for a nice middle partway along a spectrum: Exercising means challenging your body enough to respond but not so much that you hurt yourself. Astronomers look for potentially habitable planets in the”Goldilocks zones” around other stars, the bands where it’s not too hot and not too cold. It’s appropriate to … More When is a mixture better than a middle?