25 April 2024
OECDの年次レポート「Taxing Wages 2024」は、賃金にかかる税金が家計や労働市場に与える影響等を分析しています。今年の特集では、second earners（本レポートの2人以上の成人を含む世帯類型において稼得所得が少ない方の配偶者。ほとんどのOECD諸国において、少なくとも女性が４分の３を占める）の税制優遇措置と、それが労働市場における男女格差にどのように影響するかに注目。加えて、2023年の所得税や社会保障負担率の動向も詳しく解説されています。
実質所得の減少
物価高を受け、2023年には名目所得が増加した一方、多くの国で実質税引き後所得が減少。
税負担率の上昇傾向
2023年、OECD加盟国の多くで労働所得の税負担率を示す「税のくさび（tax wedge）」（雇用主にとっての労働コストとこれに対応する従業員の手取り収入の差のこと。〔従業員と雇用主が支払う所得税と社会保障負担金の合計 － 政府から受給する現金給付〕／雇用主の総労働費用で表される。）が上昇。特に平均的な賃金を得ている単身労働者の税負担率は、前年より0.13ポイント増の34.8%に。
家族の税負担
子供がいる世帯では、税負担率が家族構成や収入割合によって異なります。例えば、共働き夫婦（片方が平均賃金の100%、もう片方が平均賃金の67%の収入）の税負担率は29.5%で増加傾向。これは、片方だけが働き平均賃金の100%を稼いでいる片働き夫婦の税負担率（25.7%）や平均賃金の67%を稼ぐシングルペアレントの税負担率が16.5%を上回る。
ジェンダー視点の税制分析
second earnersは女性である場合が多く、就労や収入増加時に単身労働者よりも高い実効税率に直面しがちであるが、近年ではその税負担は緩和される傾向。
原文
Abstract
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. The results also enable quantitative cross-country comparisons of labour cost levels and the overall tax and benefit position of single persons and families on different levels of earnings. The publication shows average and marginal effective tax rates on labour costs for eight different household types, which vary by income level and household composition (single persons, single parents, one or two earner couples with or without children). The average tax rates measure the part of gross wage earnings or labour costs taken in tax and social security contributions, both before and after cash benefits, and the marginal tax rates the part of a small increase of gross earnings or labour costs that is paid in these levies.
Executive Summary
Effective tax rates on labour income edged up across the OECD in 2023 while inflation remained above historic levels. With tax systems in many OECD countries not fully adjusting to inflation, the average tax wedge1 for all eight household types covered in this Report increased in a majority of countries between 2022 and 2023, driven in most cases by higher income taxes. For the second consecutive year, post-tax incomes at the average wage level declined across a majority of OECD countries.
For the single worker earning the average wage, the OECD average tax wedge in 2023 was 34.8%, an increase of 0.13 percentage points (p.p.) with respect to 2022. This was the second consecutive year in which the tax wedge for this household type has risen, following two years of decline during the COVID-19 pandemic in 2020 and 2021. The tax wedge increased in 23 of the 38 OECD countries between 2022 and 2023, decreased in 13 and stayed the same in two. The increase exceeded one percentage point in Australia (2.14 p.p.), due to growth in nominal earnings and the elimination of a tax relief, and Luxembourg (1.39 p.p.), also due to higher nominal earnings. The decreases in the tax wedge for the single worker earning the average wage were all smaller than one percentage point, ranging from -0.01 p.p. in Canada to -0.98 p.p. in Mexico.
The OECD average tax wedge for the two-earner couple with two children (one earning 100% of the average wage, the other earning 67% thereof) increased by 0.06 p.p. between 2022 and 2023 to 29.5%. For this household type, the tax wedge increased in 21 countries and decreased in 17. The OECD average tax wedge for the couple with one earner and two children increased by 0.08 p.p. between 2022 and 2023 to 25.7%. The difference between the tax wedge for this household type and that of the single worker earning the average wage increased by 0.04 p.p. to 9.1 p.p. between 2022 and 2023.
The only decrease in the average tax wedge between 2022 and 2023 was observed for the single parent of two children earning 67% of the average wage. The tax wedge for this household type decreased by 0.31 p.p. to 16.5% in 2023, increasing in 21 countries and declining in 17. The largest decrease in the tax wedge for this household type – of -13.1 p.p. – occurred in the Slovak Republic and was due to a temporary increase in the child tax credit and an increase in child cash transfers. In 2022, the tax wedge for this household type increased by 1.27 p.p., the largest increase observed for any of the household types that year.
The Report contains a Special Feature on the tax wedge on second earners in OECD countries. This chapter sheds light on how tax policy may affect the incentives facing women when they decide whether and how much to work, in a context of persistent gender-related inequalities in labour outcomes, particularly as concerns the labour force participation of women (who account for over 75% of second earners and two-thirds of part-time workers in most OECD countries). The chapter uses the Taxing Wages models to calculate the effective tax rates on a second earner who takes up employment or increases the amount they work, which it compares with that of a single worker. Except in countries with individual taxation, the average tax wedge of second earners who take up employment is higher than that of single workers at the same wage level, although the second-earner tax wedge has declined in recent years. The marginal tax wedge for a second earner who increases their earnings is similar to that of a single worker.
