Since the time of Ben Franklin, few sayings have been as popular as "time is money," and that aphorism seems especially relevant among busy entrepreneurs. It's a pithy reminder that lost productivity often translates to lost revenue. But despite being as common as dirt, is this saying and the mindset it represents actually causing us harm?

That's the suggestion of new research published in the Journal of Experimental Psychology. The small study used 53 Canadian college students as guinea pigs to test the knock-on effects on our psychology of thinking of time and money as interchangeable.

The researchers conducted a series of three experiments that encouraged some participants to think of time and money as interchangeable by calculating their hourly wage from their earnings. Others weren't asked to make this calculation but all participants were then given time to relax and their happiness was measured afterward.  Here's what they found, according to the paper:

Experiment 1 demonstrated that thinking about one's income as an hourly wage reduced the happiness that participants derived from leisure time on the Internet.

Experiment 2 revealed that a similar manipulation decreased participants' state of happiness after listening to a pleasant song and that this effect was fully mediated by the degree of impatience experienced during the music.

Finally, Experiment 3 showed that the deleterious effect on happiness caused by impatience was attenuated by offering participants monetary compensation in exchange for time spent listening to music, suggesting that a sensation of unprofitably wasted time underlay the induced impatience.

Or to put it simply, thinking about the monetary value of our time when we're relaxing makes us impatient and unable to enjoy our leisure time. The implications are pretty straightforward for business owners: pondering exactly how much you could be making when you're supposed to be relaxing prevents you from properly winding down when you're off the clock.

Maybe it's time to remind yourself of the value of the other non-monetary values of loafing, including boosted creativity, stress reduction, time to reflect on big-picture questions and perhaps even improved relationships if you spend some of that leisure time with those you care about.