One way to stop those nasty fights over money

This post comes from Lynn Mucken of MSN Money.

I'm a sucker for any list or quiz, and especially those little fill-in-the-numbers calculators that predict how long you will live or whether you will outlast your money.

My results: I will live to be 92, but if I make it to 100, I will leave a seven-figure estate. Of course, the first calculator failed to take into account that no male member of my family has lived beyond 73, while the second ignored even the possibility of that recent financial unpleasantness.

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Naturally, I couldn't ignore a CNBC.com article titled "9 major money mistakes that can derail your marriage." I learned that my wife, Nancy, and I have pretty much stumbled from disaster to debacle instead of building the solid financial philosophy essential to a happy marriage.

So, how has the relationship survived for 44 years? Separate checkbooks.

It sounds so simple now, but it was a journey long and strange. Like most folks, I suspect, we fought over money because we didn't have any. I still remember a particularly intense and loud argument that brought our wide-eyed younger daughter to tears. The stakes were substantial: Should we spend $12 on a pair of jeans for the older sister?

Similar battles -- like two crows tussling over the last french fry in a McDonald's parking lot -- went on for more than a decade. We thought they were over the money, although by that time there always seemed to be plenty. In truth, they were over control of the money.

"I didn't like feeling that I had to come and ask you for money," recalls Nancy, who ran the household as a stay-at-home mom with two little kids. "I didn't like being reluctant to write a check because you might have forgotten to enter the last one you wrote." As sole wage earner, I chafed at having to get permission for even minor spending. Post continues after video.

Then one morning, Nancy, who had gone back to college to get her RN degree and had been hired at a hospital in Portland, Ore., announced, "I'm going to get my own checking account." Not a request, not a discussion, just a statement of fact.

Unspoken guidelines

If there were negotiations over who would pay for what, I don't recall them. At first, I paid all the bills and Nancy "chipped in" when needed, especially for vacations. Now, more than 30 years later, it has evolved to this: Nancy takes care of the credit card, phone, Internet, cable, utilities and gasoline, while I write the "big checks" (taxes, insurance, car payments, condo dues, remodeling).

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But here's the unique thing: Neither of us has the faintest idea how much is in the other's bank accounts. It is basically "don't ask, don't tell." Nancy is still working, while I am dependent on Social Security, a small pension and a few dollars from freelance editing or writing. So occasionally she asks, "Need help with that?" And last year, when we were planning our "once-in-a-lifetime"​ vacation, the financial discussion consisted of a single question from me: "Can you handle this?"

Still, there are never-spoken guidelines. I asked Nancy what hers are.

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"I wouldn't buy anything, such as furniture you would have to live with, without talking to you," she answered. "So we discuss purchases to find a plan and a timeline. If I had to put a number on it -- anything over $500.

"Of course, if it was something just for me, like an iPad -- or golf clubs in your case -- no discussion would be necessary."

Not surprisingly, those are my guidelines, right down to the dollar amount.

An offshoot of this is another unspoken rule: I never look in her purse and she never opens my wallet.

This philosophy works for us, but we have friends who take it further by having separate accounts, plus a household account each contributes a set amount to every month. And we have friends who share a single account -- and even an e-mail address (something we would never do). They all seem to get along just fine.

"It's all about respect," Nancy explains. "We are a couple, but we are not joined at the hip. You are who you are and I am who I am."

More from MSN Money:

• Can you stop a money train wreck?
• Signs a mate may be hiding money
• Get real! Marriage is a business
• 6 marriage-killing budget issues
• Budgeting and savings: Some tips
• How to handle your parents' finances