If you’ve wondered how people actually spend their money once they’reretired, a new study from the Michigan RetirementResearch Center at the University of Michigan can help you out.

Americans who save for retirement throughout theirworking lives, the study found, often hold tight to those fundsafter they retire.

While couples’ retirement spending patterns keeptheir wealth relatively stable over time, the study found, thatchanges—as one might expect—once they start paying for such thingsas medical care, nursing homes and other end-of-life expenses.

Researchers looked at the spending patterns of more than 4,600households over a 15-year period, using a subset of the Health andRetirement Study that collects data on the health and wealth ofpeople over age 70.

Wealth included savings and retirement accounts, investments,and home equity.

They compared how couples in two different income groups spenttheir money. The average couple at the 20^th percentilehas about $14,000 in postretirement income, and $70,000 in wealthat age 74; the 80^th percentile couple has more than$30,000 in income and $330,000 in wealth.

What the researchers found was that, as long as both spouseslived, wealth stayed pretty much the same regardless ofincome/wealth level. However, once one spouse died, patternsdiffered.

For the higher-income couples, during the year of the firstspouse’s death, wealth fell by about $60,000, with the biggestchunks of money going toward medical and nursing home care.

But for the lower-income couples, while wealth also dropssharply if the husband is the first to die, it changes very littleif the wife dies first.

Again, unsurprisingly, after the death of the second spouse,while higher-income couples have enough left to provide an estatefor their heirs, the assets of lower-income couples have prettywell been depleted.

So why do people hang onto their money so strongly once they’veactually managed to retire?

The researchers suggest that a “significant fraction of allassets held in retirement are used to self-insure against the riskof high medical and death expenses.”