Book excerpt: This annual publication provides details of taxes paid on wages in OECD countries. This year’s edition focuses on fiscal incentives for second earners in the OECD and how tax policy might contribute to gender gaps in labour market outcomes. For the year 2023, the report also examines personal income taxes and social security contributions paid by employees, social security contributions and payroll taxes paid by employers, and cash benefits received by workers. It illustrates how these taxes and benefits are calculated in each member country and examines how they impact household incomes.