Massachusetts real gross domestic product grew 5.9 percent in the third quarter of 2017 according to the MassBenchmarks Current Economic Index, released today by MassBenchmarks, the journal of the Massachusetts economy published by the UMass Donahue Institute in collaboration with the Federal Reserve Bank of Boston. Nationally, real gross domestic product grew at a 3.0 percent annualized rate during the same period according to the U.S. Bureau of Economic Analysis (BEA).