The rates for self-employed workers are, on average, similar to those faced by employees, although there are significant differences across countries. Nevertheless, there are important differences in the impact of social contributions across countries, in particular between countries with high rates of self-employed contributions and those where self-employed contributions are set at a fixed amount. As a benchmark, this chapter uses a broad definition of atypical or NSW arrangements that, following international convention, includes any temporary, part-time and own-account self-employment work: taken together, this kind of employment comprises a sizeable share (33%) of total employment in the OECD, shared roughly equally between temporary jobs, permanent part-time jobs and self-employment. The shares of non-standard employment range from a low of under 20% in some eastern European countries to 46% or more in the Netherlands and Switzerland.