Perhaps someone can explain to me how the ability to fire people more easily will boost the labor participation rate?

Is it that the fear that once a firm hires someone they will never be able to let them go in case of a business downturn?

As far back as I can remember, the drumbeat from business associations has been exactly that. It never made sense to me, but then again I'm not an employer.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman