Gross domestic product increased at an annual rate of 1.7% in the fourth quarter, a slight upward revision from last month's estimate, according to final numbers released by the Commerce Department's Bureau of Economic Analysis Thursday. In the third quarter, real GDP increased 4.1%. Real GDP measures the output of goods and services produced by labor and property located in the U.S. The government said in February that fourth-quarter GDP had risen at a 1.6% rate. The increase in real GDP in the fourth quarter primarily reflected positive contributions from private inventory investment, personal consumption expenditures, exports, equipment and software, and residential fixed investment. Partly offsetting that was the negative effect from federal government spending. Imports, a subtraction in the calculation of GDP, increased. The price index for gross domestic purchases, which measures prices paid by U.S. residents, increased 3.7% in the fourth quarter, 0.1 percentage point more than the preliminary estimate. Excluding food and energy, the price index for gross domestic purchases rose 3.2% in the fourth quarter. Real personal consumption expenditures were up 0.9% in the fourth quarter, compared with an increase of 4.1% in the third quarter. Current-dollar GDP -- the market value of the nation's output of goods and services -- rose 5.2%, or $160.4 billion, in the fourth quarter to a level of $12.77 trillion.