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Trying to figure our whether mid-career folks like myself are adequately preparing for retirement can get a bit confusing. If you look at Boston College’s National Retirement Risk Index (NRRI), as of 2013 as many as 52% of households aged 30-59 are at risk of falling at least 10% short of being able to produce an adequate “replacement rate” of income.

That doesn’t sound too good, does it? But a discussion of the methodology of this survey and others at a recent meeting of the Retirement Research Consortium in Washington D.C., shows that things might not be so dire after all.

It turns out that the NRRI might be setting an unrealistically high bar for retirement income. The index's replacement rate assumes that a household’s goal is to maintain a spending level in retirement that is equal to their pre-retirement living standard. It also includes investment returns on 401(k)s and IRAs in its calculation of pre-retirement income, even though those earnings are specifically earmarked for post-retirement. By including those investment gains, the NRRI may be targeting a replacement rate that is too high, causing more households to fall short, as Sarah Holden, director of retirement and investment research at the Investment Company Institute, pointed out in the meeting.

It’s already hard for someone in their 30s or 40s to figure out how much they need to be contributing today to replace the income they will have right before they retire. Adding to this guessing game is the debate over whether spending really goes down in retirement. You'll pay less for work lunches, commuting expenses, and so on, but you might spend more for travel in the early years of retirement and, later on, more for health care costs.

In contrast to the NRRI calculations, many financial planners assume that would-be retirees will automatically cut spending when their children turn 21, and therefore only need to replace about 70% to 80% of their pre-retirement income. But as Frederick Miller of Sensible Financial Planning explained at the consortium’s meeting, that’s simply not the case anymore. He sees many clients continuing to support their adult children, helping them to pay for health insurance, rent, graduate school or a down payment on a home. While generous, this support obviously detracts from retirement savings.

So which assumption is correct? Should we be saving with the expectation of spending less in retirement or not? In reality, we should certainly prepare for eventually reducing consumption since, in the long run, we may have no choice about doing so. When spending does decline after retirement, it is almost twice as likely due to inadequate financial resources rather than voluntary belt-tightening, as Anthony Webb of Boston College discovered in a small survey of households.

The question of how much is enough will vary greatly by household. But it's clear that my generation, and those that follow, face stiff headwinds—longer life expectancy, a likely reduction in Social Security benefits, and low interest rates, which greatly reduce the ability to generate income. Cutting back on spending during retirement, as well as during our working years, may be the single greatest contributor to our financial security that we can control.

Konigsberg is the author of The Truth About Grief, a contributor to the anthology Money Changes Everything, and a director at Arden Asset Management. The views expressed are solely her own.