Money market funds and cash equivalents (short-term certificates of deposit, T-bills) will yield below 1.0 percent for several more years, thereby generating a negative real return.

FORBES: The Next 10 Years

T-bills yield a negative real rate of return now and 10-year Treasuries yielding 4% don't light my fire.

FORBES: Magazine Article

T-bills normally yield a 1% real rate of return.

FORBES: Magazine Article