When you retire, there's likely a good two to three decades of living to look forward to. But the amount your dollar buys in the first year of retirement will shrink over the next years due to inflation. 

Average inflation rates in the U.S. have been about 3.2% over the last century—pretty low by international standards. That figure masks a lot of variance, though. Over-40s might remember the 1970s, when inflation rates hit double digits. In general, beating inflation requires a return on investment of at least 4% to 6% per year, in addition to whatever income is generated or saved for. 

Accordingly, here are some strategies for investors, as well as financial advisors, might want to adopt.

Rent Your House

If you own your house, renting part of it out can be a nice inflation hedge because rental prices reflect local inflation. If the location is good, raising rents over time won't impact getting a tenant.

More senior citizens are renting out space out of necessity. If you're retired, the double whammy of inflation and interest makes renting out that spare bedroom a more attractive option. (See also: How to Rent Your Home so You Can Pay Your Mortgage.)

Can you use your house to save for retirement? Probably not. There is a huge difference between monetizing  real estate that you own and investing for retirement. In order to turn a profit on a property, it's necessary that its value increases faster than inflation and the interest rate on the loan, which might be an additional 3% to 5% at least. So one's real estate would have to gain value at rates approaching 6% every year at a minimum, and more likely double digits. Outside of a real estate bubble, that isn't likely. There are many good reasons to buy a home—building equity is one—but investing for retirement is probably not one of them. (See also: The Complete Guide to Becoming a Landlord.)

TIPS

Treasury Inflation-Protected Securities, or TIPS, are a kind of government-backed bond introduced in 1997. Unlike conventional treasury bills, TIPS have an adjustable principal, linked to the Consumer Price Index, and a fixed coupon rate. That means that as inflation rises (or falls) the amount of money that goes to the holder varies with it.

On the plus side, there's no danger that inflation will get high enough to make them money losers, unlike conventional bonds. A coupon rate of 3.5% does no good if inflation reaches 4%. The risk, though, is when inflation is negative or extremely low. Deflation doesn't happen often–the last major deflationary period in the U.S. was the Great Depression. Even the Great Recession didn't manage a negative rate—the closest was in 2008, when inflation hit 0.1%. A very low inflation rate can, however, push treasury yields into negative territory as investors panic and rush to the relative security of T-bills. (See also: Shield Your Portfolio from Inflation.)

Annuities

Annuities can offer inflation protection, depending on the type. An annuity is basically "retirement insurance." You pay a premium, and at the end of a certain term, you get a fixed monthly payment. (See also: An Overview of Annuities.)

Fixed annuities generally win out here. The combination of lower fees and the security that comes with not having to worry about the value of the underlying assets makes them better for most people.

Variable annuities are annuities that offer higher returns if the market does well. One can continue to make contributions after retirement, and sometimes they are taxed at a lower rate. They have higher fees, though, and are complex investments. (See also: Inflation-Protected Annuities: Part of a Solid Financial Plan.)

Mutual Funds, Stocks, ETFs

Of course, there's always just traditional investing for income: putting money into mutual funds, stocks or exchange-traded funds (ETFs) and living off the returns. If one invested just $1,000 in the stock market in January 1994, in a fund that tracked the S&P 500, the net worth would be $9.344, as of Jan. 6, 2018, That is a return of 848%. 

Funds, stocks and ETFs are all very liquid, and even if one accounts for capital gains, the tax rate is considerably less (about 20% at the high end). Dividends are taxed at the ordinary rate, but long-term capital gains—which is anything held for a year or more—are not.

In retirement, though, the concern is usually providing a stream of income, rather than growing the assets. And as the saying goes, "timing is everything." Anyone who put money into that S&P 500 fund in 2003, when markets hit lows in the wake of the dot-com bubble and the 9/11 attacks, would have lost money by 2008. Had they pulled out in late 2007 they'd have doubled their investment. The difference is only a few months. Many soon-to-be-retirees had to keep working in the wake of the financial crisis because so much of their wealth was tied up in stocks. (See also: Will You Have to Delay Your Retirement?)

Social Security

Then we have the old standbys: defined-benefit plans and Social Security. Social Security is a "fixed income," but it has a cost-of-living adjustment. And delaying retirement can go a long way too: For a worker making about $50,000 (the median income) who is about to retire and is 65, the benefit is $1,302 per month. But if they delay until they are 67 that check goes up to $1,556. Social Security by itself isn't much, of course, but in combination with savings and a 401(k) plan, it can help a lot. (See also: Delaying Social Security Can Add Up.)

Defined-benefit plans (if you're lucky enough to have one) often structure benefits according to the last few years of salary. Delaying retirement can boost the monthly amount, providing a further hedge against inflation even if the check is a fixed number.

The Bottom Line

There are several strategies for managing inflation in your or a client's retirement savings. Most likely, a combination of the above strategies will be employed to ensure that purchasing power is protected and savings drawdown doesn't happen too fast.