Purchase-mortgage originations are expected to increase slightly in 2018, but not enough to offset declines in refinance activity, according to industry analysts. On average, economists at Fannie Mae, Freddie Mac and the Mortgage Bankers Association project that $1.21 trillion in purchase mortgages will be originated next year, up 5.9 percent from the amount expected in 2017. “All the pieces are in place for stronger growth in 2018 and beyond,” Michael Fratantoni, the MBA’s chief economist ...