Consumer spending slowed. Personal consumption expenditures advanced at a 1.8% pace during a period of healthy job growth and steady wage gains, suggesting a degree of caution among households. Even so, consumer spending remained a mainstay of economic growth during the quarter.A year ago the Congressional Budget Office and Federal Reserve thought gross domestic product would expand 2.3% in 2019. The private sector projected 2.2%. The final number: 2.3%. Of course, the path was somewhat tortuous. It took three interest rate cuts by the Fed, along with the 2018 tax cut, to keep household consumption growing strongly and turn housing from a drag in 2018 to a minor boost in 2019. Federal spending also made a substantial contribution. Goods exports and business investment were big disappointments, both declining over the course of the year. The Trump administration expected both to benefit from its trade and tax policies; its own forecast of 3.2% economic growth was badly off the mark. (That projection also assumed all of its policies would pass Congress, which didn't happen).If global growth picks up, trade tensions ease and Boeing’s 737 Max returns to the air, 2020 should be better.HousingThe housing sector finished strong. Residential fixed investment—purchases of private residential structures and equipment—advanced at a 5.8% pace, the strongest in two years. The housing sector was a drag on growth in 2018 and the first half of 2019 but that's reversed. The Federal Reserve's interest-rate cuts likely supported the market.CautionConsumer spending slowed. Personal consumption expenditures advanced at a 1.8% pace during a period of healthy job growth and steady wage gains, suggesting a degree of caution among households. Even so, consumer spending remained a mainstay of economic growth during the quarter.The UglyBusiness investment faltered—again. Nonresidential fixed investment fell for the third consecutive quarter. That's the longest contraction since the great recession and suggests GOP tax cuts didn't lead to the kind of sustained spending boom advocates had touted. There was one bright spot in the underlying details: Companies have been spending on software, an investment that could pay off with increasing productivity in the future.Trade WindsTrade provided the biggest boost to economic growth in a decade. The way GDP is calculated, exports add and imports subtract from the final tally. Last quarter, exports advanced a little and imports collapsed. GubmintU.S. government spending has been a consistent driver of growth during the Trump administration. Federal expenditures and investment have added to GDP for 11 straight quarters, the longest such stretch since the recession and its immediate aftermath. Year over year, federal spending and investment is growing at the fastest pace since 2010.Final WordThe latest numbers will get revised. But as of now, President Trump still hasn’t hit 3% annual growth. GDP advanced 2.3% in 2019—whether you measure it from fourth quarter to fourth quarter or stack one full year against the next.