Factories are busier. Incomes are rising. Autos are selling. The holiday shopping season is shaping up as the best in four years. Stock prices are surging.

And many analysts are raising their forecasts for the economy’s growth. Goldman Sachs, for instance, just revised its gloomy prediction of a 2 percent increase in gross domestic product in 2011 to 2.7 percent and forecast 3.6 percent growth for 2012.