It’s not only middle-class Americans that are worried about the country’s economic future, but affluent Americans as well.

On Friday TNS released a new study that revealed that 87% of Americans with $500,000 or more in investable assets feel that the size of the US government's deficit is a major concern for them.

Of those surveyed, 40% state that they would be willing to pay higher taxes if it meant there were no changes to Social Security and Medicare, according to TNS. In addition, 40% said they would be willing to accept changes to both Social Security and Medicare to balance the budget. Meanwhile, 43% feel the current state of the economy will jeopardize their retirement plans, 40% plan to reduce the amount of money they spend compared to last year.

Fifty-six percent said that they are concerned that the US government may default on its debt obligations, and 60% stated they do not think the U.S. government should increase the federal debt ceiling.

TNS’ Investor Confidence Index, declined in June to 102, an 11-point drop, its lowest level in a year.  This is due to increased pessimism about the stock market and the direction of the economy.

“These findings reveal significant stress and discomfort among investors who control the overwhelming majority of the personal wealth in the U.S.,” said Joe Hagan, SVP at TNS, in a press release. “We expect investor confidence to decline further if a decision concerning the debt ceiling isn't made ahead of the August 2nd deadline.  On the other hand, a satisfactory resolution could raise investor confidence and spur a rise in the financial markets.”

The TNS Investor Confidence index is a composite measure of confidence based on investor expectations for the next six months.  The most recent measure is based on a survey conducted online June 22 – 29, 2011.  The statistics cited here reflect the answers of 1,685 respondents who had total investable assets of $500,000 or more.