Since the early 1990s, the OECD has sought to accurately measure regulations concerning the dismissal of regular employees and hiring of workers on temporary contracts. This chapter presents the latest estimates for OECD countries and selected emerging economies (including all G20 countries). They are the result of a comprehensive effort to update the OECD indicators, based on a more accurate collection methodology and taking account not only of legislation but also of national or branch-level collective agreements and case law, where relevant. This effort has also led to a significant revision of historical time series. First, countries with the strictest regulations as regards notification, negotiation and authorisation requirements before notice of termination of employment can be served tend to have also restrictive provisions in at least some other areas (e.g. severance pay or the definition and costs of unfair dismissals). Second, two alternative models of employment protection emerge.