A new study from Schroders sheds light on why so many Americans and others aren’t saving enough for retirement: They underestimate how much money they’ll actually need.

The survey of 22,000 people in 30 countries — including 1,606 in the U.S. — found that pre-retirees aged 55 and older underestimate the necessary levy of retirement savings by 13 percentage points. They expect to need 76% of their current salary in retirement but have only 63% on average.

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In the U.S. the gap is 16 percentage points — expecting 74% of their current salary to live on but saving only 58%. The gap is narrower in Europe, at nine percentage points, but wider in Asia at 17 percentage points.

In the U.S. and in many other countries, pre-retirees are underestimating their everyday living expenses in retirement. Americans estimate that living expenses will eat up about 32% of their income when in actually it accounts for 54%. Their expectations for health care spending surprisingly is in line with actual spending levels —15% compared to 14%.

Despite these disconnects between saving levels and spending outlays, 92% of U.S. retirees surveyed report that they have sufficient income, though roughly half say they could use a little more. In comparison, 85% of retirees globally report sufficient income, also with about half preferring to have more.

In addition, U.S. retirees report allocating 22% of their income to investing, far more than the 9% that U.S. pre-retirees are expected to allocate. This was also a universal occurrence. Globally, retirees allocated 19% of their income to investing versus expectations of allocating only 9%.

“Perhaps as a result of not having enough in retirement, our study showed that retirees were continuing to invest, and this often represented a larger amount than they expected prior to retirement, ” said Lesley-Ann Morgan, global head of retirement, in a statement.

Respondents reported using several sources to help them make investment decisions, including their own research from third-party sources, a financial advisor (defined broadly to also include bank manager, insurance broker and accountant as well as more traditional financial advisors), pension provider and company, and family and friends.

Asked to rate the importance of their own research from a third party or information from a financial advisor on a scale of 1 to 10, respondents in the U.S. gave the same 8.0 rating for both. In almost all other countries surveyed financial advisors were considered less important a resource than an individual’s own research from a third party.

— Check out How to Become a 401(k) Millionaire on ThinkAdvisor.