Whenever I’m poring over grocery ads and clipping coupons, I wonder: Are we big food spenders compared to our parents’ and grandparents’ generations? I don’t feel like we buy a lot of expensive or convenience food, yet somehow I’ve always had a gut instinct that we are spoiled shoppers compared to the families who came before us.

And eating out? I remember going out maybe once every other week when I was a kid in the 1970s. My own family today (2 parents, 2 kids) goes out slightly more often—maybe twice a week. And my husband eats lunch out more often than my dad (a consummate brown-bagger). So I often feel a pang of guilt when we pay a restaurant bill.

Then I read this interesting book, which really opened my eyes. Turns out we aren’t entirely the “Overspending Generation” we guilt ourselves out to be.

Harvard professor Elizabeth Warren did a comprehensive comparison of American spending patterns in the 1970s compared to today. And guess what: We aren’t blowing our paychecks on expensive restaurant meals and designer clothes after all.

Consider this, according to Warren’s research:

* Today’s average family of four does spend more at restaurants than its 1970 counterpart but it spends much less at the grocery store. Our generic paper towels and Costco-brand cereals more than make up for our eating out. In fact, Warren’s research shows that today’s family spends 22 percent less on all food (restaurants and grocery stores combined) than a family in the early ‘70s! (And yes, prices have been adjusted for inflation, so Warren is comparing apples to apples.)

* Clothing: Even when you add up our mall spending sprees and our habit of outfitting our kids at Gap and Gymboree, today’s family spends 21 percent less on clothes than a 1970s family. How is this possible? Clothes are cheaper. Consider how many items you can pick up at Old Navy for less than $100. Then think about your mom or grandma and her tailored wool suits and last-forever leather shoes. We may buy more clothes today, but we are still spending a lot less.

* Appliances: Today’s families spend a whopping 44 percent less on necessities—even when you add in new appliances like microwaves and dishwashers—than families of a generation ago.

* Luxury entertainment: Yes, we spend more on cable TV, large-screen TVs, DVDs and the like. However, Warren’s research shows that our electronic expenditures (including home computers) are more than offset by how much we’re saving on appliances and furniture.

Other trades:

– We spend more today on airline travel, but less on dry cleaning.
– We pay more for telephone service but buy less tobacco.
– We pay more for pets and their needs, but less on carpets.

So why is it so hard to get ahead today? Pure and simple, according to Warren and her coauthor-daughter: Amelia Warren Tyagi: Housing costs. They’ve increasing astronomically, as you’ve probably noticed. Yes, our parents and grandparents stretched to buy homes, but not as much as we do today. Even folks who are buying reasonably sized homes and not “McMansions” must fork out a much higher percentage of their income for their house than previous generations.

Before you wag your finger too hard at the folks who foolishly bought houses they couldn’t afford, consider who helped them do it: Financial institutions. When our parents bought homes, they couldn’t even qualify for a mortgage if it took up too much of their monthly income. Home equity loans? Our parents had to bring in paystubs and the detailed plans for the family room they were adding on, and sit down with their loan officer to discuss it in person. Loans were hard to get.

In recent years, though, banks’ lending regulations loosened up. As a result, unscrupulous mortgage lenders were able to “help” families get into houses with no money down or interest-only loans. Loan officers let buyers foolishly commit to homes that took up much more than a quarter of their income (the percentage many financial planners say is wise). The mortgage crisis has started to end that practice—thank goodness—but much of the damage has already been done.

Of course, we’ve all got to be responsible for our own buying decisions. And it’s always important to stick to a budget. But as long as you’re a reasonably careful shopper, it may be time to stop beating yourself up about not being as disciplined a spender or saver as your parents were.

If your granddad could have bought his home with no money down, he might actually have done it, smart as he was. If your mom could have bought clothing cheaply at WalMart, you probably would have ended up with a few more pairs of shoes as a kid.

I may still feel a little uneasy when we eat out, but not as much as I did before I read Warren’s book. She reminded me that every generation has different economic choices. Not necessarily better or worse—just different.