BMO economist explains huge underperformance of TSX. Plus, this Canadian bank stock may now be a buy

BMO senior economist Robert Kavcic has detailed the stark underperformance of the Canadian economy and stock market relative to the United States in his weekly column. Domestic investors can be forgiven a degree of trepidation when choosing TSX stocks over S&P 500 companies, at least until interest rates begin to fall. Mr. Kavcic notes that Canada's real GDP growth of about 1 per cent over the past 12 months trails the U.S.'s 3.2 per cent by a significant margin. This comes despite Canada's immigration surge, which should theoretically have boosted the economy. Domestic per capita GDP growth now trails the…