Long-term returns for U.S. public pensions are expected to drop to the lowest levels ever recorded, portending deeper pain for states and cities as a $1 trillion funding gap widens.

Twenty-year annualized returns for public pensions in the U.S. are poised to decline to 7.47% once fiscal 2016 results are released in coming weeks, according to an estimate from Wilshire Trust Universe Comparison Service, which tracks pension investment returns.

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