More than 650 economists, including five winners of the Nobel Prize for economics, released a statement Wednesday calling for an increase in the official U.S. minimum wage. The federally-mandated minimum wage of $5.15 an hour has not been adjusted since 1997, and the value of that last increase has been “fully eroded,” leaving the current wage at its lowest real value since 1951, the statement said. The economists dismissed claims by critics that increasing the minimum wage would create hardship for small businesses and possibly lead to greater unemployment. The benefits accrued to low-income workers by raising the minimum wage would far outweigh the negative consequences to employers, they said. A gradual increase in the federal minimum wage to $7.25 “falls well within the range of options where the benefits to the labor market, workers, and the overall economy would be positive,” the statement said. “The weight of the evidence suggests that modest increases in the minimum wage have had very little or no effect on employment.” The economists included Nobel prize winners Kenneth Arrow of Stanford University, Lawrence Klein of the University of Pennsylvania, Robert Solow of the Massachusetts Institute of Technology, Joseph Stiglitz at Columbia University and Clive Granger of the University of California, San Diego. Twenty-two states and the District of Columbia have set their minimum wages above the current federal level.