This post is from staff writer Sierra Black. Sierra writes about frugality, sustainable living, and getting her kids to eat kale at Childwild.com.

Shopping momentum is the bane of many budgets. You may have a good grip on your money most of the time, but once you’ve opened up your wallet to make one purchase, it’s easy to just keep spending.

People sometimes experience shopping momentum during times of stress or transition: when they’re traveling, when there’s a crisis at home or at work, during a big life change like a move or welcoming a new baby. You’ve just laid out a lot of money for an unusual expense, and something in your brain tells you it’s time to spend more.

Shopping momentum
Crazy as it sounds, this is a real psychological phenomenon. Research at the Stanford Graduate School of Business showed that people who buy one item are more likely to continue buying others.

Essentially, the decision to buy anything — from a house to a toothbrush — involves two steps:

  1. Choosing, and
  2. Buying

In the first step, you weigh your options and carefully consider your choices. Once you’ve made a decision, your brain shifts gears to the “buying” mode. In that mode, it’s easy to keep buying. Your buying brain doesn’t stop to carefully consider your alternatives on each purchase; it just throws stuff in the cart and keeps going.

Shopping momentum in real life
I worried about shopping momentum during our recent trip to Argentina. From past experience, I know I spend more when I’m traveling and when I’m stressed. Traveling with young kids is stressful, so our Argentina trip featured at least two budget danger zones for me.

My worries were unfounded. While in Argentina, I barely spent anything at all. We stayed with family, and spent most of our time hanging out with family and friends. I was concerned about how much the trip cost, and so was very focused on keeping our incidental expenses low. At the end of the month, we flew home with a third of the money I had set aside for the trip unspent.

All that changed when we landed. Coming home was wonderful, but suddenly we were facing a wall of pent-up need:

  • There were, of course, no groceries at all in our house. We needed to go grocery shopping — right away.
  • I’m traveling for a business conference this week, where I’ll also be running my first 5K race. A look through my closet confirmed that I needed new clothes for the trip. And new running shoes.
  • My husband and kids had needs too.

Pretty soon, we’d stacked up a lot of expensive requests — enough to spend all the money we’d saved on our trip…and then some. Some of these needs are real, of course. We really do need groceries. I really do need appropriate shoes and clothing for the conference and the race. But once I’d started buying, the expenses piled up fast. I “needed” a haircut, and new lip gloss, and…

What I really needed was to take a deep breath and recognize what was happening.

Just because I’m doing some stressful, exciting things doesn’t mean I have to spend a lot of money. In the end I got away with buying only a new bra and paying for a haircut. Everything else I was able to borrow, reuse, or do without.

Stopping shopping momentum
How can you stop shopping momentum once it gets going? The first step, of course, is to recognize it. To do that, set up some sort of mental alert for yourself, to pay attention when you have an unusual expense. There are plenty of good reasons for unusual expenses. These come up in our lives all the time, and there’s nothing wrong with spending money when you need to. The trick is to notice that you’re doing it so you don’t accidentally slip into a buying mindset.

If you have trouble taking mental note of a shift in your spending patterns, you can set your personal finance software to alert you when you’ve had unusual activity in a particular category. Mint alerts me whenever I spend more than $100 on “shopping”. It doesn’t happen very often, and it’s good to be aware when my shopping expenses are unusual.

You can also help yourself recognize shopping momentum by getting to know your financial personality. Look at your spending records each month. What kinds of situations cause spikes in your spending? Do you spend too much when you travel? When you go out with friends? On your kids? Figure out what pushes your brain into buying mode, and you’ll be able to catch it that much sooner to hit the brakes.

To stop the shopping once you’ve started, ask yourself these questions before any purchase:

  • Do I really want this?
  • Will I love it and/or use it?
  • Can I get it another, less expensive way?
  • Can this purchase wait?

A lot of times, even good purchases aren’t urgent. If you’re really struggling to slow your spending, try adhering to a 30-day list. If you see an item you want to buy, put it on a list instead of buying it. Wait 30 days. If you still want the thing after 30 days, consider buying it. You’ll be amazed at how much Stuff you’re able to just cross off your list without purchasing.

The power of conscious spending
Stopping shopping momentum is good for everyone. Even if you have plenty of money, you don’t want to end up at the end of a shopping spree with a bunch of Stuff you’re not interested in having and a big bill to pay. Shopping also soaks up valuable energy that you might rather spend on a hobby, a side job, or just relaxing with friends and family.

By mastering your buying brain, you’ll have more time and energy to pursue the things you really want.

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