The second income trap: the share of a second salary that never reaches the household, from 26.0% in Stockholm to 104.8% in Zurich

By Skyler Bissell · September 12, 2026 · 10 min read

77.2% of a $56,250 second salary never reaches a Seattle family with a three-year-old and a seven-year-old. Part of it is the income tax and payroll her salary adds to a bill that already contains her partner's; the rest is the nursery and after-school place her job makes necessary. That share is the second income trap, and it is a rate, which means it can be compared across countries the way a tax rate can. For the same family it is 26.0% in Stockholm, 45.8% in Berlin, 75.6% in London and 104.8% in Zurich, where the household has less money with her working than without.

This page defines the rate and ranks seven cities on it. The money behind each rate, salary by salary, is in the pair to this page, is it worth working after paying for childcare, and I have not repeated the ledger here.

The second income trap is the share of a second earner's gross salary that never reaches the household. It has two parts: the income tax and contributions the salary adds to the household's bill, which depends on whether the country taxes the couple together or each person alone, and the childcare the job makes necessary, which depends on whether the price of a nursery place is set by a market or capped by law. The rate is the two parts over the salary. The OECD calls the tax part a participation tax rate and prices the childcare part separately as the net childcare cost; this page adds them, because a household pays both.

TL;DR

The rate runs from about a quarter of the second salary in Stockholm to more than all of it in Zurich, with New York at 95.5% in between. The seven-city ranking.
Berlin taxes the second salary at 44.4% and London at 18.9%, on similar top rates, because Germany files the couple together and Britain does not. Multiplier one.
The best city on the page is the only one where both multipliers are small, and the worst is the one where the nursery costs more than the salary. Multiplier two.

The trap as a rate, seven cities ranked

One household throughout: two earners splitting USD 150,000 at a 100/60 ratio, children aged three and seven, a two-bedroom rental, 6% into retirement, restated in local currency abroad at a fixed ratio. The second earner is on the 60 side of the split in every city. Each rate below is what she loses, as a share of her gross, against the same household with her at home and no childcare bought; the two components are given beside it and add up to it.

Stockholm, 26.0%. Tax on her salary 20.8%, childcare 5.2%. Individual taxation since 1971 and a förskola fee capped by the maxtaxa.
Berlin, 45.8%. Tax 44.4%, childcare 1.4%. The cheapest childcare on the page and the highest tax on the second salary, under Ehegattensplitting.
Amsterdam, 48.2%. Tax 19.7%, childcare 28.5%. Individual assessment in Box 1; a market nursery price with kinderopvangtoeslag refunding part of it.
London, 75.6%. Tax 18.9%, childcare 56.7%. Independent taxation since 1990; a market nursery price at the unfunded rate.
Seattle, 77.2%. Tax 19.8%, childcare 57.4%. Married filing jointly, no state income tax, a market nursery price.
New York, 95.5%. Tax 27.2%, childcare 68.3%. Married filing jointly plus state and city income tax, and the dearest American childcare in our data.
Zurich, 104.8%. Tax 16.8%, childcare 88.0%. The lightest tax on the page and a nursery place that costs more than she earns, at the unsubsidised rate.

Engine figures, 2026, at the exchange rates in the current build. Tax is the household's income tax plus mandatory employee contributions with both earning, minus the same bill with the second earner at home, over her gross. Childcare is a full-time place for the three-year-old plus after-school care for the seven-year-old at each city's own rates, net of any subsidy the household qualifies for at this income, over her gross. Zurich's is Stadt Zürich's unsubsidised rate; the city's income-tested Betreuungsgutscheine are named and left out of the figure. London's is the unfunded Coram rate. New York's nursery price is from Care.com listings, crowdsourced and marked as such.

Two readings of that list. The order is not the order of tax rates, and it is not the order of childcare prices; it is the order of the sum, and a country can be at the top of one list and the bottom of the other. Berlin has the cheapest nursery and the dearest tax on her salary. Zurich has the lightest tax and the dearest nursery. The one city that is good on both is the one at the top.

A rate above 100% is a real result. In Zurich the household's net cash with her working is CHF 2,167 lower than with her at home, because the Kita and Hort bill of CHF 39,600 is larger than her CHF 45,000 salary before the tax on it is counted. At that point she is paying to work, in the year the children are in care. The New York to Zurich comparison for a family shows what that does to a whole household budget.

Multiplier one: who files

A country either taxes a married couple as one unit or as two people, and the choice decides what the second earner's first unit of income is charged. Under joint filing it is added to a household already partway up the progressive ladder and taxed at the household's marginal rate, with no allowance of its own. Under individual filing it starts at the bottom of its own ladder, with its own allowance and low bands, whatever the partner earns.

Germany's Ehegattensplitting under § 32a Abs. 5 EStG is the clearest joint case: the couple's taxable income is halved, run through the tariff, and the tax doubled. That rewards a household with one earner and charges the second earner her partner's marginal rate from the first euro, with pension, health, care and unemployment insurance on her gross on top, which is how Berlin's tax component reaches 44.4% on a €51,750 salary. The American joint return works the same way for federal tax: her salary lands in the married-filing-jointly brackets on top of his, so the tax component is 19.8% in Seattle and 27.2% in New York, where state and city tax stack on the federal bill. Zurich files the couple together under the cantonal Verheiratetentarif and still comes in at 16.8%, because Swiss income tax at this income is low to begin with.

Britain has taxed spouses independently since 1990. Sweden has since 1971. The Netherlands assesses employment income per person in Box 1 whatever the fiscal partner earns. In all three the second salary is taxed as a single person's would be, so the tax component is 18.9% in London, 20.8% in Stockholm and 19.7% in Amsterdam. The gap between Berlin and London on this component, on similar top rates, is the filing rule and nothing else. The mechanism behind "the second earner's first dollar is taxed at the household's marginal rate" is set out in marginal vs effective tax rate, which named this trap before I had a number for it.

Multiplier two: what a nursery place costs

The childcare component is a price divided by a salary, so it is large wherever the price is set by a market and small wherever a law caps it. Zurich's Kita and Hort take 88.0% of her salary at the unsubsidised rate, New York's nursery 68.3%, Seattle's 57.4%, London's 56.7% at the unfunded rate. Amsterdam's is 28.5% after kinderopvangtoeslag, a refund that exists only while both parents work. Stockholm's maxtaxa holds the fee to 5.2%, and Berlin's food money at a fee-free Kita is 1.4%.

The OECD's childcare-support indicator gives the scale of this across countries: its "typical" gross fee for two children in full-time centre-based care works out at just under 26% of average earnings across the OECD, and the net cost to a two-earner couple after benefits at just under 14%, on 2018 data updated in April 2022. Its household differs from mine (children aged two and three, the first earner on the average wage and the second on 67% of it), which is why I quote the OECD for the spread and my engine for the rate. The price behind each city's component is in childcare costs by country.

Two things follow from the childcare component being a fixed price. It shrinks as the second salary grows, so a higher-paid second earner faces a shallower trap in the same city, while the tax component grows with the salary, so the two halves move against each other. And it ends with the children's ages, whatever the income: at school age the full-time place becomes after-school care, and a few years later that ends too. Stockholm's rate then falls to its tax component alone; Zurich's falls from above 100% to below 20%. The trap is a phase of family life, priced per country.

What the rate does and does not say

It prices one year. A second earner who stays in work keeps her pension contributions, her seniority and her salary in five years; one who leaves in the nursery years often returns lower. None of that is in the rate, and all of it argues for reading a high rate as a fee for keeping a career, paid for a few years.
It holds child benefit constant. Kindergeld, barnbidrag, kinderbijslag, the Swiss Kinderzulage and the US Child Tax Credit are the same on both sides at this income. Only the childcare subsidies switch with work status, and those are counted where they apply.
It bills the market. Seattle's Child Care Assistance Program stops at USD 153,244 for a family of four, just above this household; Zurich's vouchers and London's 30 funded hours are all within reach of it in law. The engine bills the market price and names each programme beside it, which is conservative against working in those three cities.
It is a share of her salary alone. The household's own effective rate, both earners in, is a different number and sits beside the healthcare line in the true tax burden once healthcare is counted.

FAQ

Is the second income trap the same as the marriage penalty?

No, though they overlap. The marriage penalty compares a couple's tax bill married against unmarried on the same two salaries. The second income trap compares the household with and without the second salary, and it counts childcare, which the marriage penalty never does. A country with no marriage penalty can still have a deep trap: Britain taxes spouses independently and London's rate on this page is 75.6%, almost all of it the nursery bill.

Does the second income trap apply to a single parent?

The tax half largely does not, because there is no first salary to stack the second on, so a single parent's salary meets the ordinary bands. The childcare half applies in full, and the alternative to working is no earned income at all, because there is no partner's salary to fall back on. The OECD runs its childcare-cost indicator for a lone parent as well as a couple for that reason. Our single-parent scenario, two children and one salary, sits under every comparison page as the with-kids variant.

At what salary does the trap disappear?

It does not disappear with salary; it changes shape. The childcare half is a fixed bill, so its share falls as the second salary rises: double the salary and the nursery takes half the share. The tax half rises with the salary in every country, and faster in the joint-filing ones. What ends the trap is the children's ages. The full-time place ends at school age and the after-school care a few years later, and from then on the rate is the tax half alone.

How do I calculate my own second income trap rate?

Take the household's tax bill with both salaries and subtract the bill with only the first; add the childcare bill the second job makes necessary; divide by the second salary. Our calculator does the two tax runs for you: enter both salaries, note net cash, untick the box for your partner working and set care to none, note net cash again, and the difference over the second salary is one minus your rate.

The money behind every rate on this page, city by city and line by line, is in is it worth working after paying for childcare. The framework both pages hang off, with the parental leave year that neither of them prices, is the cost of raising kids. The Seattle to Stockholm comparison for a family runs the two ends of the ranking against each other for a published household, and the calculator runs yours.

Sources. The participation-tax-rate and net-childcare-cost concepts and the OECD-average figures quoted above: OECD Family Database, PF3.4 Childcare support (updated April 2022, 2018 data), retrieved 12 September 2026. Filing rules: § 32a EStG (Ehegattensplitting); IRS, tax year 2026 inflation adjustments (married filing jointly); HMRC, income tax rates; Skatteverket and the Belastingdienst for individual assessment in Sweden and the Netherlands; the ESTV Rundschreiben Nr. 215 and Zürich § 35 Abs. 2 StG for the married tariff. Childcare prices: the US Department of Labor, National Database of Childcare Prices (Seattle); Care.com listings for New York, crowdsourced and marked as such; the Berlin Senate, Kostenbeteiligung; Coram's Family and Childcare Survey for London; Skolverket's maxtaxa for Stockholm; the Belastingdienst kinderopvangtoeslag tables for Amsterdam; Stadt Zürich, Kita for Zurich. Every other value carries its own source and date in data/_meta.json, and our price lines split between official and crowdsourced sources as described in the methodology.

Figures here come from cityparity's per-city engine and were current at publication; fees, benefit amounts and exchange rates move, so treat any single number as a strong estimate and run your own inputs. Where our comparison pages quote an equivalent salary, it is the bar an offer has to clear in the destination city and it is not a job offer. See the methodology.