Monthly GDP decreased 0.2% in August

Monthly GDP decreased 0.2% in August after a 0.9% increase in July. The decrease in August was driven by large decreases in net exports and nonfarm CIPI. Final sales to domestic purchasers posted a moderate gain in August for the fourth consecutive month, reflecting gains in personal consumption expenditures and nonresidential fixed investment. The level of monthly GDP in August was 3.5% above the second-quarter average at an annual rate. Implicit in our latest tracking forecast of 3.7% annualized GDP growth in the third quarter is a second small decrease in September.

S&P Global Market Intelligence’s 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.