In a recent interview, Theresa May was asked by Andrew Neil how the Conservatives would fund their manifesto commitments on NHS spending. Given that the Conservatives chose not to cost their manifesto pledges, May was unable to answer. Instead she simply repeated that the Conservatives are the only party that can deliver the economic growth and stability required to pay for essential public services. When pressed, May’s response was simple: ‘our economic credibility is not in doubt’.

Does the record of the last seven years support May’s claim?

The first statistic always quoted in such discussions is GDP growth. A lot has been made of the latest quarterly GDP figures, showing the UK at the bottom of the G7 league with quarterly GDP growth of just 0.2%. But these numbers actually tell us very little: they refer to a single quarter and are still subject to revision.

It is more useful to look at real GDP per capita over a longer period of time. This tells us the additional ‘real’ income available per person that has been generated. The performance of the G7 countries since the pre-crisis peak in 2007 is shown in the chart below, with the series indexed to 1 in 2007 for each country. (Data are taken from the most recent IMF WEO database.)

GDP per capita in the UK only surpassed its pre-crisis level in 2015. By 2016, GDP per capita relative to the pre-crisis level was less than 2% higher than in 2007, putting the UK behind Japan, Germany, the US and Canada, slightly ahead of France, and well ahead of the Italian economy which remains mired in a deep depression. On this measure, the UK’s performance is not particularly impressive.

For most people, wages are a more important gauge of economic performance than GDP per capita. Here, the UK is an outlier. Relative real wage growth in the G7 economies is shown in the table below, alongside the changes in GDP per capita for the period 2007-2015.

Despite coming mid-table in terms of GDP per capita, the UK has the worst performance in terms of real wages, which have fallen by an average of 1% per year over the period. Even in depression-struck Italy, wages did not fall so far.

This translates into a fall of almost five percent in the real wage of the typical (median) worker since the crisis, as the chart below shows. This LSE paper, from which the chart is taken, finds that while almost everyone is worse off since the crisis, the youngest have seen the largest falls in income with 18-21-year-olds facing a fall in real wages of over 15%

With the value of the pound falling since the Brexit vote, inflation is once again eating into real wages and the latest figures show that, after a period of a couple of years in which wages had been recovering, real wages are now falling again and are likely to do so for the next few years. Average earnings are not projected to reach 2007 levels again until 2022 – by then the UK will have gone fifteen years without a pay rise.

A related issue is the UK’s desperately poor productivity performance. ‘Productivity’ here refers to the amount produced per worker on average. As the chart below from the Resolution Foundation shows, the UK has now experienced a decade without any increase in productivity — something which is historically unprecedented.

What causes productivity growth is a controversial topic among economists. Until recently, the majority view was that productivity is not affected by government macroeconomic policy. This position (which I disagree with) is increasingly hard to defend. As Simon Wren-Lewis argues here, evidence is mounting that the UK’s productivity disaster is the result of government policy: the Conservatives’ austerity policies have caused flatlining productivity.

Austerity — or, as it was branded at the time, the ‘Long Term Economic Plan‘ — was the central plank of Osborne’s policy from 2010 until the Brexit referendum vote in 2015.

As I and others have argued at length elsewhere, austerity was based on two false premises — ‘lies’ might be more accurate. The first was that excessive spending by Labour was a cause of the 2008 crisis. The second was that the size of the UK’s government debt posed serious and immediate risks that outweighed other concerns.

One thing that almost all macroeconomists agree on is that when recovering from a severe downturn such as 2008 — and with interest rates at nearly zero — the deficit should not be the target of policy. Instead, it should be allowed to expand until the economy has recovered.

Simply put, the deficit should not be used as a yardstick for successful management of an economy in the aftermath of a major economic crisis such as 2008. But since eliminating the deficit was the single most important target of the Conservatives’ so-called Long Term Economic Plan, we should examine the record.

In 2010, Osborne stated that the deficit would be eliminated by 2015. Two years after that deadline passed, the current Conservative manifesto states — in a passage that would not pass any undergraduate economics exam — that they will ‘aim to’ eliminate the deficit by 2025.

Even on their own entirely misguided terms, they have failed completely.

While the dangers of the public debt have been vastly exaggerated by the Conservatives, they have had little to say about private sector debt. It is now widely accepted that the only remaining motor of economic growth is consumption spending. But with wages stagnant, continued growth of consumption cannot be sustained without rising levels of household debt.

This is the reason given when economists are asked why their predictions of post-referendum recession were so wrong: they didn’t anticipate the current credit-driven consumption burst. But this trend has been apparent for at least the last two years. It shouldn’t have been too hard to see this coming.

Just as the Tories tend to stay quiet on private debt, they also have little to say about the ‘other’ deficit — the current account deficit. This is a measure of how much the country is reliant on foreigners to finance our spending. The deficit expanded from 2011 onward to reach almost 5% of GDP. This is an important source of vulnerability for a country which is about to try and extricate itself from economic integration with its closest neighbours.

Overall, the Tories economic record is far from impressive: stagnant wages and productivity, weak investment and manufacturing, rising household debt, and a large external deficit.

Now, a reasonable response might be that these are long-standing issues with the UK economy and are not the fault of the Conservatives. There is some truth to this. But if this is the case, Theresa May should identify and acknowledge these issues and provide a clear outline of how her policies will address them. This is not what she has done. Instead, she simply repeats her mantra that only the Conservatives will deliver on the economy, without providing any evidence to support her claim.

And then there is the decision to call a referendum on Brexit. It is hard to think of a more economically reckless move. Household analogies for government economic policy should be avoided — but I can’t think of an alternative in this case.

Following up on an austerity programme with the Brexit referendum is like sending the children to school without lunch money for six years and allowing the house to fall into serious disrepair in order to needlessly over-pay a zero-interest mortgage — and then gambling the house on a dice game.

Given this record, it is astonishing that the Conservatives present themselves, with a straight face, as the party of economic competence — and the media dutifully echoes the message. The truth is that the Conservatives have mismanaged the economy for the last seven years, needlessly imposing austerity, choking off growth in productivity, wages and incomes. They then called an entirely unnecessary referendum, gambling the future prosperity of the country for political gain.

Theresa May is correct — there is little doubt about the economic credibility of the Conservatives. It is in short supply.