An excellent learning exercise for students of economics is to take a journal article that uses data to model the economy and then try to replicate the authors’ results. You may well be given an assignment like this in future years of your degree.
One such exercise is used on the University of Massachusetts Amherst’s doctoral programme in economics. Thomas Herndon is a student on that degree and chose to examine a well-known and highly influential paper, Growth in a Time of Debt by Carmen Reinhart then of the University of Maryland and Kenneth Rogoff of Harvard University and former chief economist of the IMF. Professors Reinhart and Rogoff used new data on 44 countries spanning about 200 years.
A key finding of their paper, published in 2010 in the American Economic Review Papers and Proceedings, is that once a country’s government debt exceeds 90% of GDP, growth rates fall considerably: the median across countries by about 1% and the mean considerably more.
The paper has been hugely influential. It has been used to justify the austerity programmes being pursued in many countries, including the UK and the eurozone. Cutting the government deficit to GDP ratio, and ultimately the government debt to GDP ratio, has been seen as a way of achieving higher growth over the longer term, and justifies the adverse effect on short-term growth from the dampening of aggregate demand.
Well, this seemed an interesting paper for Thomas Herndon to examine, and he was keen to show just how Reinhart and Rogoff’s data led to their conclusions. But try as he might, he could not replicate their results. His initial reaction was to think he had made an error, but each time he checked he came back with the same conclusion: they must have made errors in their calculations.
His supervisor at Amherst, Professor Michael Ash, after Thomas had checked and checked again, realised that something was wrong. He encouraged Thomas to write to Reinhart and Rogoff to request sight of their dataset. They duly obliged and it was then that Thomas spotted various errors. These are explained in the articles below, but the overall effect was to alter the conclusion. Although high debt may undermine growth to some extent, the effect is much less than Reinhart and Rogoff concluded, and there are several exceptions to this rule.
On 15 April 2013, Thomas, along with his supervisor, Michael Ash and his colleague, Robert Pollin, published a response to the Reinhart and Rogoff paper. In the abstract to their paper, Does High Public Debt Consistently Stifle Economic Growth? A Critique of Reinhart and Rogoff they state that:
… coding errors, selective exclusion of available data, and unconventional weighting of summary statistics lead to serious errors that inaccurately represent the relationship between public debt and GDP growth among 20 advanced economies in the post-war period. They find that when properly calculated, the average real GDP growth rate for countries carrying a public-debt-to-GDP ratio of over 90 percent is actually 2.2 percent, not –0:1 percent as published in Reinhart and Rogoff. That is, contrary to RR, average GDP growth at public debt/GDP ratios over 90 percent is not dramatically different than when debt/GDP ratios are lower.
The authors also show how the relationship between public debt and GDP growth varies significantly by time period and country. Overall, the evidence we review contradicts Reinhart and Rogoff’s claim to have identified an important stylized fact, that public debt loads greater than 90 percent of GDP consistently reduce GDP growth.
So could this be you in the future? Will you take a famous paper and, by re-examining and reworking the data, find that its conclusions are wrong? Could you end up changing the world? Exciting stuff!
Podcasts
Austerity: A Spreadsheet Error? BBC, More or Less, Tim Harford (20/4/13)
Austerity justification study ‘inaccurate’ BBC Today Programme, Robert Pollin (18/4/13)
Articles
UMass Student Exposes Serious Flaws in Harvard Economists’ Influential Study The Atlantic Wire, J.K. Trotter (18/4/13)
Shocking Paper Claims That Microsoft Excel Coding Error Is Behind The Reinhart-Rogoff Study On Debt Business Insider, Mike Konczal (16/4/13)
How a student took on eminent economists on debt issue – and won Economic Times of India (19/4/13)
Meet the 28-Year-Old Grad Student Who Just Shook the Global Austerity Movement New York Magazine, Kevin Roose (19/4/13)
An economist’s mea culpa: I relied on Reinhart and Rogoff Confessions of a Supply-Side Liberal blog, Miles Kimball (22/4/13)
The Rogoff-Reinhart data scandal reminds us economists aren’t gods The Guardian, Heidi Moore (18/4/13)
Reinhart, Rogoff… and Herndon: The student who caught out the profs BBC News Magazine, Ruth Alexander (20/4/13)
George Osborne’s case for austerity has just started to wobble The Guardian, Polly Toynbee (18/4/13)
The error that could subvert George Osborne’s austerity programme The Guardian, Charles Arthur and Phillip Inman (18/4/13)
The Excel depression Sydney Morning Herald, Paul Krugman (19/4/13)
Europe: Retreat from austerity BBC News, Gavin Hewitt (23/4/13)
Guest post by Thomas Herndon
The Grad Student Who Took Down Reinhart And Rogoff Explains Why They’re Fundamentally Wrong Business Insider, Thomas Herndon (22/4/13)
Papers
Growth in a Time of Debt NBER working paper, Carmen M. Reinhart and Kenneth S. Rogoff (January 2010)
Does High Public Debt Consistently Stifle Economic Growth? A Critique of Reinhart and Rogo ff PERI Working Paper 322, Thomas Herndon, Michael Ash and Robert Pollin (April 2013)
Questions
- What were the particular errors made by Reinhart and Rogoff?
- How has their paper been used as a basis for the design of macroeconomic policy?
- What are the limitations of using even accurate time-series data as the basis for policy measures?
- How might the work of Herndon change the direction of future macroeconomic policy?
- In his guest post in Business Insider (see link above), Herndon wrote: ‘The implication for policy is that, under particular circumstances, public debt can play a key role in overcoming a recession.’ What might this role be?
- Why might we have to be cautious in drawing policy conclusions from Herndon’s work?
Much has been written on Margaret Thatcher following her death at the age of 87 on April 8. But getting a calm assessment of both her time in office and her legacy is not easy. And it’s clear why: she created both stronger loyalty and stronger opposition than any other UK Prime Minister.
As economists, however, we should try to be as dispassionate as possible in assessing the effects of policies. There is always a normative question of the relative desirability of different economic outcomes – and you will have your own views on the relative importance of objectives such as economic growth, greater equality and greater social cohesion – but to determine cause and effect, or at least correlation, requires a careful examination of the evidence. Also, drawing lessons for future policy requires a careful modelling of the economy and the effects of changing economic variables.
The following articles have been selected from the hundreds that have appeared in the press in the past few days. Whilst they cannot be claimed to be totally ‘objective’, taken together they give a good overview of her economic policies and her economic legacy.
You may well have been surprised by the amount of coverage of her death and at the fervour of her supporters and critics. But this bears witness to the huge effect she had on both the political scene and on the UK economy – for good or bad.
Articles
Margaret Thatcher’s timeline: From Grantham to the House of Lords, via Arthur Scargill and the Falklands War Independent (8/4/13)
Overhauls Are Still Felt, Debated Decades Later Wall Street Journal, Charles Forelle (9/4/13)
Margaret Thatcher’s Four Ages of Monetary Policy EconoMonitor, David Smith (10/4/13)
How Mrs Thatcher smashed the Keynesian consensus The Economist (9/4/13)
Margaret Thatcher: The economy now and then BBC News, Stephanie Flanders (10/4/13)
Did Margaret Thatcher transform Britain’s economy for better or worse? The Guardian, Larry Elliott (8/4/13)
A look back at Margaret Thatcher’s economic record Washington Post, Dylan Matthews (8/4/13)
Margaret Thatcher’s legacy for business and economics—the world weighs in Quartz, Gwynn Guilford (8/4/13)
Data
Economic Data freely available online The Economics Network, see especially sites 1, 2, 3, 6 and 9
Questions
- Summarise the macroeconomic policies followed by the Thatcher government from 1979 to 1990.
- Chart economic growth, unemployment and inflation over Margaret Thatcher’s time in office. How does the performance of each of these indicators compare with the period from 1990 to 2007 and from 2008 to the present day?
- What is meant by ‘monetarism’? Did the Thatcher government follow pure monetarist policies?
- What is meant by the ‘Big Bang’ as applied to the financial sector in 1986? Assess the long-term consequences of the Big Bang.
- What elements of ‘Thatcherism’ were retained by the Labour government from 1997 to 2010?
- To what extent can the current Coalition government be described as ‘Thatcherite’?
The UK economy faces a growing problem of energy supplies as energy demand continues to rise and as old power stations come to the end of their lives. In fact some 10% of the UK’s electricity generation capacity will be shut down this month.
Energy prices have risen substantially over the past few years and are set to rise further. Partly this is the result of rising global gas prices.
In 2012, the response to soaring gas prices was to cut gas’s share of generation from 39.9% per cent to 27.5%. Coal’s share of generation increased from 29.5% to 39.3%, its highest share since 1996 (see The Department of Energy and Climate Change’s Energy trends section 5: electricity). But with old coal-fired power stations closing down and with the need to produce a greater proportion of energy from renewables, this trend cannot continue.
But new renewable sources, such as wind and solar, take a time to construct. New nuclear takes much longer (see the News Item, Going nuclear). And electricity from these low-carbon sources, after taking construction costs into account, is much more expensive to produce than electricity from coal-fired power stations.
So how will the change in balance between demand and supply affect prices and the security of supply in the coming years. Will we all have to get used to paying much more for electricity? Do we increasingly run the risk of the lights going out? The following video explores these issues.
Webcast
UK may face power shortages as 10% of energy supply is shut down BBC News, Joe Lynam (4/4/13)
Data
Electricity Statistics Department of Energy & Climate Change
Quarterly energy prices Department of Energy & Climate Change
Questions
- What factors have led to a rise in electricity prices over the past few years? Distinguish between demand-side and supply-side factors and illustrate your arguments with a diagram.
- Are there likely to be power cuts in the coming years as a result of demand exceeding supply?
- What determines the price elasticity of demand for electricity?
- What measures can governments adopt to influence the demand for electricity? Will these affect the position and/or slope of the demand curve?
- Why have electricity prices fallen in the USA? Could the UK experience falling electricity prices for similar reasons in a few years’ time?
- In what ways could the government take into account the externalities from power generation and consumption in its policies towards the energy sector?
VAT was introduced on the 1st of April 1973, as part of the conditions for the UK entering the Common Market. Designed by a French tax expert, Maurice Lauré, it was initially envisaged as a straightforward replacement for purchase tax, which would be applied to most goods and services.
Forty years on, VAT is increasingly complex, with numerous exemptions, many anomalies in its scope, and increasingly expensive challenges to its imposition. How did we get to this point? And is it time for VAT to undergo a mid-life makeover?
All governments have to raise taxes – to redistribute income and to fund public spending. They have a number of mechanisms they can use, but essentially they have to tax incomes (direct taxes), spending (indirect taxes) or a mix of both. The main indirect tax in the UK is VAT, which now raises over £100bn a year, compared with £1.5bn in its first year (see above chart: click here for a PowerPoint version). Initially envisaged as a simple, cross-Europe purchase tax, the current system is complex and at times appears to have been formulated ‘on the hoof’, never a good way to build a tax system.
In the 2012 Budget, the Chancellor decided to apply the standard rate of income tax to hot takeaway pasties; previously they had been zero-rated. However, he had sharply underestimated the ability of the industry to lobby against the tax, working closely with the tabloid press. Perhaps more importantly, he also missed the complex nature of the good; when is a hot pasty just cooling down? And what is hot? The government backtracked and now 20% VAT is only charged on pasties that are deliberately kept hot. You might think that this change of heart avoided introducing an anomaly, but consider how you might feel if you sell takeaway baked potatoes, which are subject to VAT.
Apart from the complexity of the system, VAT is unpopular with some commentators who feel that it falls too heavily on low-income households. Although many foodstuffs are zero-rated and housing is exempt, VAT is charged at 20% on clothing and many necessities such as cleaning materials. Gas and electricity are subject to a reduced rate of 5% and both alcohol and cigarettes have additonal excise duties imposed and yet are disproportionally consumed by the poor. When the standard rate of VAT was temporarily dropped to 15% in 2010, but then permanently raised to 20% in 2011, many felt that this was a shift in the tax burden to the poor.
So complex, irrational and prone to changes following political lobbying or expensive legal cases, VAT does seem to be stumbling into its forties under something of a cloud. However, it remains the case that it raises a large proportion of UK tax revenues at relatively low direct cost and provides the Chancellor with a reasonably effective fiscal policy tool. Even if a government wanted to put in place an alternative, it is likely that the associated political risks would be too high for it to do so. We might hope for some rationalisation of the current system, but there is little doubt that we will be raising a glass to VAT’s 50th birthday in 2023.
The links below include some articles on VAT’s 40th birthday and some more general articles on VAT.
Articles
VAT is 40 years old- and now has middle-age spread The Guardian, Juliette Garside (31/1/13)
Is VAT suffering a mid-life crisis at 40? BBC News, Colin Corder (31/3/13)
VAT at 40, not simple, not popular, but central to government revenue-raising The Chartered Institute of Taxation (28/3/13)
Happy birthday VAT, here’s how not to pay you The Telegraph, Rosie Murray-West (31/3/13)
Poorest spend higher proportion of VAT than richest BBC News (31/10/11)
A Value- Added Tax offers much to love- and hate New York Times, Gregory Mankiw (1/5/10)
EC Standard VAT Declaration European Commission Roadmap (2012)
Data and information
VAT pages HMRC
Public sector finance statistics HM Treasury (follow link to latest Public finances databank (Excel file) and go to Worksheet C2)
Latest European Union EU VAT rates VATLive
Questions
- Explain why VAT might be deemed regressive. Can you formulate an argument that it falls more heavily on the rich than the poor?
- Why is VAT administratively cheap? Other than generating tax revenues, can you think of any advantages of the tax?
- Newspapers and books are zero-rated in the UK, while e-books and news apps are standard rated at 20%. Can you identify some other anomalies in the UK VAT system? Is there an argument that a better approach would be to charge a lower rate on all goods and services?
- Who pays VAT, consumers or producers? Illustrate your answer with a diagram, or two.
- A business has to register for VAT once it has a turnover of £77,000 pa. Does this system give rise to any perverse incentives?
- Countries across the European Union have varying VAT rates, applied to very different ranges of products. Explain why this might hinder the workings of a single European market.
- Imagine you were running a brand new economy; would you use a value-added tax to raise revenues? What are the alternatives open to governments?
The UK government has just given the go-ahead for the building of two new nuclear reactors at Hinkley Point in Somerset. The contract to build and run the power station will go to EDF, the French energy company.
The power station is estimated to cost some £14 billion to build. It would produce around 7% of the UK’s electricity. Currently the 16 nuclear reactors in the UK produce around 19%. But all except for Sizewell B in Suffolk are due to close by 2023, although the lives of some could be extended. There is thus a considerable energy gap to fill in the coming years.
Several new nuclear power stations were being considered to help fill this gap, but with rising capital costs, especially following the Fukushima disaster in Japan, potential investors pulled out of other negotiations. Hinkley Point is the only proposal left. It’s not surprising that the government wants it to go ahead.
All that remains to agree is the price that EDF can charge for the electricity generated from the power station. This price, known as the ‘strike price’, is a government-guaranteed price over the long term. EDF is seeking a 40-year deal. Some low carbon power stations, such as nuclear and offshore wind and wave power stations, have high capital costs. The idea of the strike price is to reduce the risks of the investment and make it easier for energy companies to estimate the likely return on capital.
But the strike price, which will probably be agreed at around £95 per megawatt hour (MWh), is roughly double the current wholesale price of electricity. EDF want a price of around £100 per MWh, which is estimated to give a return on capital of around 10%. The government was hoping to agree on a price nearer to £80 per MWh. Either way, this will require a huge future subsidy on the electricity generated from the plant.
There are several questions being asked about the deal. Is the strike price worth paying? Are all the costs and benefits properly accounted for, including environmental costs and benefits and safety issues? Being an extremely long-term project, are uncertainties over costs, performance of the plant, future market prices for electricity and the costs of alternative forms of power generation sufficiently accounted for? Will the strike price contravene EU competition law? Is the timescale for construction realistic and what would be the consequences of delays? The articles consider these questions and raise a number of issues in planning very long-term capital projects.
Articles
Hinkley Point: Britain’s second nuclear age given green light as planning permission is approved for first of new generation atomic power stations Independent, Michael McCarthy (19/3/13)
Will they or won’t they? New nuclear hangs in the balance ITV News, Laura Kuenssberg (19/3/13)
Hinkley Point C: deal or no deal for UK nuclear? The Telegraph, Alistair Osborne (19/3/13)
New nuclear power plant at Hinkley Point C is approved BBC News (20/3/13)
Britain’s Plans for New Nuclear Plant Approach a Decisive Point, 4 Years Late New York Times, Stanley Reed and Stephen Castle (15/3/13)
Nuclear power plans threatened by European commission investigation The Guardian (14/3/13)
New Hinkley Point nuclear power plant approved by UK government Wired, Ian Steadman (19/3/13)
Renewable energy providers to help bear cost of new UK nuclear reactors The Guardian, Damian Carrington (27/3/13)
Europe backs Hinkley nuclear plant BBC News (8/10/14)
Information/Reports/Journal Articles
Environmental permitting of Hinkley Point C Environment Agency
NNB Generation Company Limited, Radioactive Substances Regulations, Environmental Permit Application for Hinkley Point C: Chapter 7, Demonstration of Environmental Optimisation EDF
Greenhouse Gas Emission of European Pressurized Reactor (EPR) Nuclear Power Plant Technology: A Life Cycle Approach Journal of Sustainable Energy & Environment 2, J. Kunakemakorn, P. Wongsuchoto, P. Pavasant, N. Laosiripojana (2011)
Questions
- Compare the relative benefits of a construction subsidy and a subsidised high strike price from the perspectives of (a) the government (b) EDF.
- What positive and negative externalities are involved in nuclear power generation?
- What difficulties are there in valuing these externalities?
- What is meant by catastrophic risk? Why is this difficult to take account of in any cost–benefit analysis?
- What is meant by a project’s return on capital? Explain how discounted cash flow techniques are used to estimate this return.
- What should be taken into account in deciding the rate of discount to use?
- How should the extra jobs during construction of the plant and then in the running of the plant be valued when making the decisions about whether to go ahead?
