Is the marriage tax splitting system doomed? Klingbeil's reform plans and what's really behind them

It's the tax model that has stood like an institution for decades – but now it's looking seriously shaky. Lars Klingbeil, the heavyweight of the SPD, has an idea that's making many married couples sit up and take notice: he wants to abolish marriage tax splitting. Or at least overhaul it so drastically it no longer fits with the times. I remember discussions years ago when this topic was first treated like a taboo. Back then, the line was: "It's untouchable." Today, with the state having to watch every penny, things suddenly look different.

Why Klingbeil has marriage tax splitting in his sights

The reasoning Klingbeil gives is simple – but it hits the mark. The model, where married couples are assessed jointly and their tax burden is evened out, dates from a time when the wife usually stayed at home and the husband was the sole breadwinner. Frankly, it's an anachronism today. If you look closely, you quickly realise: Marriage tax splitting doesn't support the family, but rather a specific role model. It's hugely beneficial for couples with a large income disparity – and in the vast majority of cases, that still means the classic set-up where the wife earns less or doesn't work at all.

Within the SPD, there's long been a belief that this model is a real obstacle to equality. And the figures back them up. I looked at one of the major studies on this a while ago, produced by a renowned economic research institute. They clearly show: if marriage tax splitting were abolished, women's employment would rise by an average of up to eight per cent. These aren't fantasy numbers; they're tangible effects. Suddenly, it wouldn't be worth it for many couples to have one partner stay at home just to claim the tax advantage.

What it means for the birth rate – the opposite of what you might think

Now here's what's really surprising. Advocates of the system always say: "It's the backbone of the family, it secures children." But the reality is different. A study I read in a specialist journal some time ago proved the exact opposite. When the state stops rewarding unequal income distribution and instead invests in childcare options and genuine freedom of choice, the birth rate rises. It sounds paradoxical, but it's logical: couples are more likely to feel they can have children if they know they can both work without being penalised by the tax system.

So the current debate about reforming marriage tax splitting is no longer purely about finances. It's about the question: does the state want to support the traditional breadwinner marriage, or does it want to support modern models of living? I think many younger couples no longer have that traditional idea in their heads at all. They ask themselves: why should I be penalised by the tax system just because we both work full-time and send our children to nursery?

• Fact 1: Marriage tax splitting costs the state billions in tax revenue every year.
• Fact 2: It only benefits couples with large income differences – and often those are the ones who least need it.
• Fact 3: Countries like Sweden or France have completely different models that boost both the birth rate and women's employment.

The grand coalition of Union and SPD? An obstacle named FDP

But it won't happen that quickly. The party members know that too. Because while Klingbeil is gaining more and more support within the SPD, it's a very different story for the Union. For the CSU, marriage tax splitting is practically sacred. But even if the next government could reach an agreement, there's the FDP waiting in the wings. The Liberals have already made the model a top priority. For them, the tax relief for marriage is a core component of their economic policy. I doubt such a law would get through the Bundesrat without a huge row.

But one thing must also be said clearly: simply abolishing it without offsetting measures elsewhere would be a disaster. If the system is scrapped, other tax relief must be introduced. Otherwise, the middle of society would be the loser. And that's exactly what the negotiations currently happening behind the scenes are about. It's not about abolition for its own sake, but about a reform that ultimately is fairer. Perhaps a family tax split that gives more weight to children. Or a model that recognises actual care work, regardless of marital status.

I'm telling you: the debate about marriage tax splitting will continue to occupy us intensively in the coming months. Because it sharply focuses the discussion currently taking place in this country: how do we want to live, how do we want to work, and what is that actually worth to the state? Stay tuned – it's going to be a heated autumn.