This paper studies formal employment dynamics using linked employer–employee data from eight countries spanning a wide income range from Kenya to Chile. First, we show that formality rates increase with development, both between and within countries, because more workers enter the formal sector, not because they spend more time in formal jobs. Second, formal labor market fluidity increases with development, as workers hold more formal jobs, spend less time in each job, and less time between jobs. Third, greater fluidity is associated with higher life-cycle wage growth, which is largely accounted for by within- rather than between-firm wage gains.