Whither Mexican Immigration?

Mexican immigration to the United States declined precipitously in the wake of the Great Recession and has continued to fall in subsequent years, resting at lows not seen since the start of mass Mexican immigration to the U.S. in the 1940s. Indeed, in five of the past six years, the number of return migrants to Mexico has exceeded those bound for the U.S. What explains the steep fall in Mexican immigration, and will it persist?