To begin with, the scale of the trend is enormous. In this regard, the spread of new, gig-based business models for linking workers to work isn’t just a limited-scale, vanguard development. Instead, the changes affecting a few hundred thousand workers in the rides and rooms industries are a tiny part of a pervasive, economywide move toward nontraditional freelance, contract or temporary work arrangements in dozens of industries. And the number of workers involved is huge. Overall, there may be as many as 68 million “independent” workers in the U.S., according to a new estimate by the McKinsey Global Institute. Within a decade, nearly half of all employed Americans may be employed this way. So the size of the trend alone underscores the need to pay attention.