Monthly GDP rose 0.1% in December 2019 following roughly no change in November that was revised down from a previously reported 0.1% increase. The moderate increase in December reflected positive contributions from personal consumption expenditures, residential investment, and nonfarm inventory investment that were partially offset by a decline in net exports. The level of monthly GDP in December was only 0.3% above the fourth-quarter average at an annual rate. Implicit in our forecast of 1.8% GDP growth in the first quarter are increases in monthly GDP that average 0.2% per month over the three months of the first quarter.

Our Index of Monthly GDP (MGDP) is a monthly indicator of real aggregate output that is conceptually consistent with real Gross Domestic Product (GDP) in the National Income and Product Accounts. The Monthly GDP Index is consistent with the NIPAs for two reasons: first, MGDP is calculated using much of the same underlying monthly source data that is used in the calculation of GDP. Second, the method of aggregation to arrive at MGDP is similar to that for official GDP. Growth of MGDP at the monthly frequency is determined primarily by movements in the underlying monthly source data, and growth of MGDP at the quarterly frequency is nearly identical to growth of real GDP.

Posted 29 January 2020 by Ben Herzon, US Economist, Insights and Analysis, S&P Global Market Intelligence and

Kathleen Navin, Economics Executive Director, US Macroeconomics, S&P Global Market Intelligence