Forecasters boosted expectations for U.S. economic growth in the first and second quarters of the year, with an improving labor market and a stable outlook for real output, a survey released on Friday showed.

Economists expect the economy to grow at an annual rate of 2.1 percent in the current quarter, up from the previous estimate of 1.7 percent growth, according to the Philadelphia Federal Reserve's quarterly survey of 46 forecasters.

The economists pegged second quarter gross domestic product at 2.3 percent, up from the previous estimate of 2 percent.

However, GDP for all of 2013 was estimated at 1.9 percent, down slightly from a previous estimate of 2 percent. U.S. growth for 2014 was estimated at 2.8 percent, up marginally from the previous forecast of 2.7 percent.

The unemployment rate was forecast to average 7.8 percent in the first quarter compared with the previous estimate of 7.9 percent, while unemployment in the second quarter was forecast at 7.7 percent, down from 7.8 percent in the previous estimate. The third quarter jobless rate was estimated at 7.6 percent, down from the previous forecast of 7.8 percent.

The monthly unemployment rate released by the government was 7.9 percent in January.

Unemployment on an annual average level was estimated at 7.7 percent in 2013, down from the previous forecast of 7.8 percent.

Economists lowered their forecasts for inflation this quarter with the headline consumer price index seen averaging 1.8 percent, down from an earlier estimate of 2.1 percent. For the year, CPI was expected to average 2 percent, down from 2.2 percent.

Core CPI, which strips out energy and food prices, was expected to rise by 1.8 percent in the first quarter, down from the previous forecast of 1.9 percent.