Labor Market Intermediation

David Autor has an essay on The Economics of Labour Market Intermediation"

"One might have speculated that in an era of rapid information flows and substantial job mobility, the importance of labour market intermediaries would wane. Indeed, the most prominent labour market intermediary, the traditional labour union, has been in secular declines for decades. Yet, the decline of labour unions is the exception rather than the rule. Two of the intermediaries discussed above – online search engines and centralised medical matches – have only recently gained prominence. And another labour market intermediary not even considered above, temporary help agencies, has risen from relative obscurity to international significance over the last two decades. "