We face this kind of decision all the time. Pitch one more customer, or go home to an early dinner with the family? Attend a career-boosting workshop or take a badly needed vacation? Apply for that high-paying job that will have you working long hours so you can pay for your children's education, or skip it for now so you can spend more time with them?

I can't tell you what the right thing is to do in each of these situations. But I can tell you there's a way to think about it that will make you happier: Value time more highly than money. That's the fascinating conclusion of a psychological study by UCLA researchers Hal Hershfield and Cassie Mogilner Holmes, who asked more than 4,400 Americans of all ages, backgrounds, and income levels whether more time or more money would make them happier. Most of them--64 percent--opted for money over time. But here's the interesting thing: The people who chose time were, on average, happier than the ones who chose money.

You might guess that the people who chose time already had plenty of money and that's why they were happier, but that would be a wrong guess. The researchers accounted for that possibility by comparing people with similar incomes and they still found that those who choose time over money are happier.

Here are some reasons why that might be--and why you should consider valuing money over time in your own decision-making:

1. People who think about time think how they'd love to spend it.

Imagine you suddenly found yourself with a free day and no obligations. You probably wouldn't think: "Oh great, now I can get all my laundry done!" Instead, you might think about going on a visit, taking a hike, going shopping or to the movies, or just curling up with a good book. The researchers found that when people thought about having more time, they thought about spending that extra time on something that was pleasurable. Conversely, when people thought about having more money, they thought about not having enough of it. That may be a reflection of our debt-addicted society, where most of us would plan to use extra cash to pay for things we've already bought, rather than things we hope to buy.

2. Money has a limited ability to make you happier.

Research shows that, in the US, increases in income make people happier only up to about $75,000 a year, and after that the happiness benefits tail off. Research also shows that spending money on other people can make you happier. So it's only true that extra money can make you happier some of the time. If you're using that extra money to pay off your bills or indulge in a luxury purchase for yourself, it may not make you happy after all.

3. Time is the only truly finite resource.

Instinctively, we all know this, whether or not we admit it to ourselves. What are the chances you'll become a billionaire? They may be slim, but it's not absolutely impossible. What are the chances you'll live to be 200? Zero.

So while money is fluid and can flow in and out of your life and bank account, each of us only has so much time on this planet. We should all think very carefully how we spend each precious day of it.