If you’re having trouble keeping your New Year’s resolutions, you might chalk it up to what MIT Professor Drazen Prelec calls “scale mismatch”—the challenge of achieving a large goal that turns on many small decisions distributed over time. No one trains for a marathon, saves up to buy a home, or completes a dissertation without piecing together contributions from many temporal selves. That includes the today-self who reasons that tomorrow would be a better day for running, saving, or writing—or who doesn’t trust her future selves to see through any project that she begins.

Reconciling immediate preferences (another half-hour of your favorite television show, say) with long-range aspirations (like learning to play the clarinet) is a familiar problem. But it can be approached from a fresh perspective by focusing on two key moves: recognizing the value in assembling right-sized lumps of resources or effort, and engineering the slices necessary to get there.

Even when it comes to money, that most fungible of resources, lumps matter. Consider, for example, taxpayers who were shocked and angry to receive smaller tax refunds from the IRS last year. Their checks shrank because they had overpaid less during the year—that is, the amounts withheld from their paychecks had more accurately tracked their tax liability. Hanging onto more of one’s own money might seem like a good thing, but that misses the significance of how the money is configured. A refund takes a lumpy form—it’s a big chunk of money all at once—while the unwithheld bits of each paycheck are so fragmented that they can scarcely be detected. Piecing together the same lump of cash from these fragments is difficult, yet a lump sum may be needed to cover an all-at-once outlay, like for a car or a home. Because lumps of cash are hard to put together and hard to do without, we should not be surprised to see people relying on the tax system to solve their cash-assembly problems.

Read more at Behavioral Scientist