WASHINGTON, Jan. 14 -- Seventy-five economists, including seven Nobel laureates in economics signed a public letter Tuesday urging an increase of the minimum wage for U.S. workers.

The Group urged to raise the minimum wage per hour from the current threshold of 7.25 U.S. dollars to 10.10 U.S. dollars by 2016, by hiking 95 cents annually starting 2014.

The increase would mean that minimum-wage workers who work full time, full year would see a hike of their current salary of about 15,000 dollars to 21,000 dollars. These proposals will also raise the tipped minimum wage to 70 percent, the letter said.

The letter was released by the Economic Policy Institute, a Washington D.C.-based think tank funded in part by labor unions. Among the signatories of the letter were Nobel Prize winners Kenneth Arrow, Peter Diamond, Eric Maskin, Thomas Schelling, Robert Solow, Michael Spence and Joseph Stiglitz.

The minimum wage has not been changed for about five years. Recent researches have shown that the increases in the minimum wage have had "little or no negative effect on the employment of minimum-wage workers, even during times of weakness in the labor market," according to the letter.

"A minimum-wage increase could have a small simulative effect on the economy as low-wage workers spend their additional earnings, raising demand and job growth, and providing some help on the jobs front. "

U.S. job market has witnessed steady improvements since October last year. U.S. private sector added 238,000 jobs in December, the largest monthly gain since November 2012, while the inflation still kept at a quite low level of 1.2 percent.