Why do we overcommit? Study suggests we think we’ll have more time in future than today

Poor forecasting is more evident for time than money

If your appointment book runneth over, it could mean one of two things: Either you are enviably popular or you make the same faulty assumptions about the future as everyone else. Psychological research points to the latter explanation. Research by two business-school professors reveals that people over-commit because we expect to have more time in the future than we have in the present. Of course, when tomorrow turns into today, we discover that we are too busy to do everything we promised. The study appears in the February issue of the Journal of Experimental Psychology (JEP): General, which is published by the American Psychological Association (APA).

Gal Zauberman, PhD, of the University of North Carolina at Chapel Hill, and John Lynch Jr., PhD, of Duke University, also learned from paper-and-pencil questionnaires (respondents to seven different surveys numbered 95, 68, 241, 61, 264, 48 and 130) that that this expectation of more time “slack,” a surplus of a given resource available to complete a task, is more pronounced for time than money.

The authors suspect that’s because every day’s a little different: The nature of time fools us and we “forget” about how things fill our days. Money is more “fungible,” freely exchanged for something of like kind — such as four quarters for a dollar bill. Write Zauberman and Lynch, “Barring some change in employment or family status, supply and demand of money are relatively constant over time, and people are aware of that. Compared with demands on one’s time, money needs in the future are relatively predictable from money needs today.”

Participants believed that both time and money would be more available in “a month” than “today,” and believed it more strongly for time than for money. A deeper investigation of a psychological phenomenon called “delay discounting,” in which people tend to lessen the importance of future rewards, showed that people also discounted future time more than both gains and losses in future money.

Zauberman and Lynch continue, “People are consistently surprised to be so busy today. Lacking knowledge of what specific tasks will compete for their time in the future, they act as if new demands will not inevitably arise that are as pressing as those faced today.” In short, the future is ideal: The fridge is stocked, the weather clear, the train runs on schedule and meetings end on time. Today, well, stuff happens.

To cross-check support for their hypotheses, the authors ran a final survey that measured the expected growth or contraction of slack time and slack money over time. They tested how those expectations predicted subsequent decisions to invest time or money at two points in time. As before, participants who expected to have more time but not more money discounted future time investments more than they discounted future money investments. Participants who expected to have more money than time showed a mirror-image pattern. Say the authors, “This is important because it demonstrates that the resource dependency we observed in the earlier experiments is explainable by changes in slack.”

Can people learn to predict future time demands more in line with reality? The authors observe, “It is difficult to learn from feedback that time will not be more abundant in the future. Specific activities vary from day to day, so [people] do not learn from feedback that, in aggregate, total demands are similar.” Money’s “slack pools” are smoother, more equal and more predictable over time.