The world’s wealthy are wary of taxes, according to an RBC Wealth Management survey of more than 1,000 respondents with at least $1 million in investable assets.

Tax changes topped a list of external factors worrying high-net-worth investors about their wealth—it was named by 48% of the respondents. Their other significant concerns are global economic uncertainty, named by 48%; domestic uncertainty, listed by 38%; geopolitical issues, called out by 34%; and tariffs and trade, which 26% called an issue.

When it came to their investment goals, 55% of the respondents said above all else it was conserving their assets for the future, while 49% said it was allowing for an extended retirement.

"With people living longer, and with housing and health-care costs skyrocketing, Americans are rightly concerned about the possibility of outliving their assets,” said Ann Senne, head of the RBC Wealth Management’s U.S. advice and solutions group, in a press release. "Even those with more financial flexibility share these concerns, which highlights the magnitude of the issue.”

A majority of the survey’s respondents, 75%, believed that it is more important now than ever to “future-proof” their wealth.

Unsurprisingly, more than one in three respondents, 37%, said that they expect to allocate toward less risky investments over the next five years, while only 6% said they would seek out more high-risk investments.

Many of the world’s wealthy are also aware that many of the conditions that led to their affluence no longer exist today. About half of the respondents, 51%, said that wealth is less easily attained or preserved now than it was a generation ago.

In fact, Angie O’Leary, head of wealth planning at RBC Wealth Management (U.S.), argued that the number of high-net-worth individuals who consider inheritance to be a driver of wealth has declined.

Yet only 8% of the respondents said that the opportunities to increase wealth have not increased—instead, most point to improvements in education, financial resources, technology and information as factors that could aid in the accumulation of wealth by younger generations.

The survey’s respondents acknowledged that they faced several challenges on their own way to achieving success: 33% said they faced a rising cost of living; 22% said they had not come from a wealthy background; and 14% said they funded their own health-care expenses.

The survey was conducted by The Economist Intelligence Unit during May and June 2019 among 1,051 high-net-worth individuals with $1 million in investable assets, 522 adult children of high-net-worth individuals, and 521 individuals who are not high-net worth yet but have incomes of more than $100,000. The survey included 629 U.S. respondents.