On 25 April 2024 the OECD released Taxing Wages 2024.

The publication gives cross-country comparisons of labour costs and the overall tax and benefit position in the OECD countries. The study analyses the income tax paid by employees, the cash benefits received by in-work families and the associated social security contributions and payroll taxes of employees and employers. The combination of these factors can affect the level of participation in the workforce and decisions by individuals and businesses on making available or taking up new jobs.

The report notes that labour taxes across OECD countries rose in 2023, partly due to the high levels of inflation. The effective tax rates on labour income increased in most OECD countries, resulting in a decline in the after-tax income of single workers on the average wage in many OECD countries.

The increase in labour taxation was driven mainly by increases in personal income tax in a majority of the OECD countries. The nominal wages increased in 37 of the 38 countries, with inflation remaining high, although real wages (adjusted for inflation) declined in 18 countries. Unless there is automatic indexation of tax thresholds and allowances the high inflation will have the effect of increasing personal tax liabilities as more income falls into higher tax brackets.

The report looks at the labour tax wedge, which is defined as total taxes on labour paid by both employees and employers, minus family benefits, shown as a percentage of labour costs. To examine the effect of each tax system on wages, the report examines eight different types of household types, that vary by the number of people in the household and the level of income. The study found, for example, that for a single worker earning the average wage, in 2023 the average tax wedge was 34.8% in the OECD countries, representing an increase of 0.13 percentage points from 2022.

A special feature in the latest edition looks at how the tax wedge differs between first and second earners. Examining the tax rates on second earners in married couples, more than 75% of whom are women in almost all OECD countries, the report notes that in the majority of OECD countries the second earners face higher effective tax rates than single workers when they take up work at the same wage level. However, in recent years this difference has become smaller.

The analysis reveals some fiscal disincentives to joining the labour force. For example, on average in the OECD countries, a second earner in a couple without children who earns 67% of the average wage is facing a tax wedge of 34.0%, compared to 31.0% for a single worker earning 67% of the average wage. The fiscal disincentive for a second earner taking up employment tends to be larger in countries where taxation occurs at the household level instead of the individual level. Also, in countries with individual-level taxation there can be a fiscal disincentive for second earners if tax reliefs are given at the household level.