Optimal tax rate for top one per cent may be as high as 83%

Paper suggests cutting taxes may divert attention to wasteful bargaining

Via Daniel Elton, a new(ish) paper (pdf) by economists Thomas Piketty, Emmanuel Saez and Stefanie Stantcheva makes the case for the optimal tax rate of the richest one per cent could be as high as 83 per cent.

The authors look at three possible ways in which top incomes respond to marginal tax rates.

The first is the "supply side" channel cited by Arthur Laffer when he developed his concept of the Laffer curve. Under this channel, marginal tax rates that are too high result in people doing less work than they otherwise would. Lower tax rates thus respond to more economic activity, and greater growth and higher tax revenue. Laffer's work was used by the Reagan administration to justify cutting the top rate in the US, from 70 per cent down to 28 per cent.

The second is the "tax avoidance" channel. This is the model cited by the Chancellor when he made the decision to cut the tax rate for top earners in Britain from 50 per cent to 45 per cent. The argument is that high tax rates increase tax avoidance, but the authors argue – in common with many of the Chancellors critics – that tax avoidance can be dealt with directly, writing that:

A better policy would be to first close loopholes so as to eliminate most tax avoidance opportunities and only then increase top tax rates.

The third is the "compensation bargaining" channel. The authors argue that:

While standard economic models assume that pay reflects productivity, there are strong reasons to be sceptical, especially at the top of the income distribution where the actual economic contribution of managers working in complex organisations is particularly difficult to measure.

As a result, top workers have ample opportunity to set their own pay, through bargaining harder or influencing compensation committees. The incentives for this economically wasteful activity are higher the lower tax rates are. Just as with the supply side model, tax cuts increase the wealth of the richest in society, but unlike that model they do not also increase growth; rather, the extra money for the rich comes from those poorer than them.

The authors, using their estimates of the elasticity of the various channels (that is, the magnitude of the effect), then calculate what the optimum rates would be. Under the first model, they find it to be roughly 57 per cent – 5 per cent higher than the top British tax rate is until the cut takes effect (National Insurance for top earners is 2per cent). Assessing the second model (Osborne's preferred argument), they find that the optimal tax rate would be 62 per cent, but argue that if the correct anti-avoidance and simplification measures were put in place, it would be 71 per cent.

The third model, however, outputs an optimal rate of 83 per cent. The authors still assume a minor supply-side effect, making up 40 per cent of the total elasticity, which is why it isn't higher. That is, they still assume that high tax rates will encourage the rich to work less, but they also assume that they will encourage the rich to put more of their effort into actual work, and less of it into "compensation bargaining".

How to decide between models one and three (the authors assume that once anti-avoidance measures are put in place, model two is the same as model one)? The former predicts that lower tax leads to more work, the latter that it merely leads to higher pay. As a result, tax cuts should be correlated with higher growth. Are they? Well, no:

As a result, the bargaining model can at least be said to be as realistic as the supply-side model; and if that's the case, the optimal top tax rate for most nations is likely to be far in excess of where it is set now.

For more, see the authors in the Boston Review, VoxEU, or their original paper (pdf).

Pictured: Laffer. No, wait, laughers. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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Calum Kerr on Governing the Digital Economy

With the publication of the UK Digital Strategy we’ve seen another instalment in the UK Government’s ongoing effort to emphasise its digital credentials.

As the SNP’s Digital Spokesperson, there are moves here that are clearly welcome, especially in the area of skills and a recognition of the need for large scale investment in fibre infrastructure.

But for a government that wants Britain to become the “leading country for people to use digital” it should be doing far more to lead on the field that underpins so much of a prosperous digital economy: personal data.

If you want a picture of how government should not approach personal data, just look at the Concentrix scandal.

Last year my constituency office, like countless others across the country, was inundated by cases from distressed Tax Credit claimants, who found their payments had been stopped for spurious reasons.

This scandal had its roots in the UK’s current patchwork approach to personal data. As a private contractor, Concentrix had bought data on a commercial basis and then used it to try and find undeclared partners living with claimants.

In one particularly absurd case, a woman who lived in housing provided by the Joseph Rowntree Foundation had to resort to using a foodbank during the appeals process in order to prove that she did not live with Joseph Rowntree: the Quaker philanthropist who died in 1925.

In total some 45,000 claimants were affected and 86 per cent of the resulting appeals saw the initial decision overturned.

This shows just how badly things can go wrong if the right regulatory regimes are not in place.

In part this problem is a structural one. Just as the corporate world has elevated IT to board level and is beginning to re-configure the interface between digital skills and the wider workforce, government needs to emulate practices that put technology and innovation right at the heart of the operation.

To fully leverage the benefits of tech in government and to get a world-class data regime in place, we need to establish a set of foundational values about data rights and citizenship.

Sitting on the committee of the Digital Economy Bill, I couldn’t help but notice how the elements relating to data sharing, including with private companies, were rushed through.

The lack of informed consent within the Bill will almost certainly have to be looked at again as the Government moves towards implementing the EU’s General Data Protection Regulation.

This is an example of why we need democratic oversight and an open conversation, starting from first principles, about how a citizen’s data can be accessed.

Personally, I’d like Scotland and the UK to follow the example of the Republic of Estonia, by placing transparency and the rights of the citizen at the heart of the matter, so that anyone can access the data the government holds on them with ease.

This contrasts with the mentality exposed by the Concentrix scandal: all too often people who come into contact with the state are treated as service users or customers, rather than as citizens.

This paternalistic approach needs to change.  As we begin to move towards the transformative implementation of the internet of things and 5G, trust will be paramount.

Once we have that foundation, we can start to grapple with some of the most pressing and fascinating questions that the information age presents.

We’ll need that trust if we want smart cities that make urban living sustainable using big data, if the potential of AI is to be truly tapped into and if the benefits of digital healthcare are really going to be maximised.

Clearly getting accepted ethical codes of practice in place is of immense significance, but there’s a whole lot more that government could be doing to be proactive in this space.

Last month Denmark appointed the world’s first Digital Ambassador and I think there is a compelling case for an independent Department of Technology working across all government departments.

This kind of levelling-up really needs to be seen as a necessity, because one thing that we can all agree on is that that we’ve only just scratched the surface when it comes to developing the link between government and the data driven digital economy. 

In January, Hewlett Packard Enterprise and the New Statesman convened a discussion on this topic with parliamentarians from each of the three main political parties and other experts.  This article is one of a series from three of the MPs who took part, with an  introduction from James Johns of HPE, Labour MP, Angela Eagle’s view and Conservative MP, Matt Warman’s view

Calum Kerr is SNP Westminster Spokesperson for Digital