Searching for higher returns to bridge looming shortfalls, public workers’ pension funds across the country are increasingly turning to riskier investments in private equity, real estate and hedge funds. But while their fees have soared, their returns have not. In fact, a number of retirement systems that have stuck with more traditional investments in stocks and bonds have performed better in recent years, for a fraction of the fees. Consider the contrast between the state retirement fund for Pennsylvania and the one for Georgia. The $26.3 billion Pennsylvania State Employees’ Retirement System has more than 46 percent of its assets in riskier alternatives, including nearly 400 private equity, venture capital and real estate funds.