U.S. payrolls grew in December, and 2012 The U.S. economy rounded out a third year of job gains with another month of employment growth in December, sending the strongest signal yet that it kept expanding even as the budget fight intensified. "Despite concerns about the 'fiscal cliff,' businesses were running so tight on labor that even a modest increase in demand forced them to hire," said Russell Price, a senior economist at Ameriprise Financial Inc. in Detroit. The S&P 500 soared 2.5 percent on Wednesday after Republicans and Democrats agreed on a compromise budget that avoided the fiscal cliff of sweeping tax increases due to take effect this year. Next, Republican leaders in the House are vowing to exact deep spending cuts from President Obama and the Democrats in exchange for raising the debt ceiling as the U.S. Treasury bumps up against its legal borrowing limit. Other reports Friday showed service industries, which account for almost 90 percent of the economy, grew in December at the fastest pace in 10 months, and demand for capital equipment such as machinery and communications gear picked up in November. Broad-based gainPayroll gains were broad-based with construction firms, manufacturers, health care companies and restaurants all adding staff in December.