By Steven Overly, The Washington Post Many economists and labor experts say the “gig economy” has grown in recent years as ride-sharing services, such as Uber and Lyft, and home-sharing sites, such as Airbnb and HomeAway, have gained popularity with consumers. More people today earn part or all of their income working as contractors for these various companies, indicating that the nature of work in certain industries may be shifting away from full-time, salaried employment. The problem, however, has been measuring the exact size of this labor pool.