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?
If you are an Irish resident, you may be feeling very worried! As Irish debt levels reach new heights, the bill will once again fall on the tax payer. Irish government borrowing is almost 12% of GDP, but with two key banks requiring a bail out, government borrowing is expected to treble this figure to some 32% of GDP. The Anglo-Irish bank requires approximately £30 billion and Allied Irish also requires more cash. The Irish Finance Minister said:
‘The state has to downsize these institutions to prevent them becoming a systemic threat to the state itself.’
The Irish have already faced a round of austerity cuts and with the latest banking catastrophe, the next round is about to start. There are concerns that the Irish economy could move into a downward spiral, with more money being removed from the economy causing more people to lose their jobs, which will weaken public finances further and mean that more borrowing will then be required. It is hardly surprising to find a pessimistic mood on the streets of Ireland.
However, with a new interdependent world, this crisis will not only be felt by Ireland. The UK exports a large amount to Ireland – more than to Spain or Italy. With Irish tax-payers facing higher burdens and unemployment still relatively high, UK exporters may feel the squeeze. Other countries on the periphery of Europe, such as Portugal, Greece and even Spain are also feeling the pressure. There are concerns of a ‘two-speed Europe’. Below are some articles about the Irish crisis. Do a search and see if you can find any information on the problems in Greece, Spain or Portugal.
Ireland: a problem soon to be shared BBC News blogs, Stephanomics, Stephanie Flanders (30/9/10)
European recovery hope grows despite Ireland’s swelling deficit Guardian, Richard Wachman (30/9/10)
Ireland bank rescue spurs global debt concerns The World Today (ABC News), Peter Ryan (30/10/10)
Irish debt yields in new record despite better job data BBC News (28/9/10)
Euro Govt-bonds fall after overdone rally on Ireland, Spain Reuters (30/9/10)
Ireland’s love affair with masochism Telegraph, Jeremy Warner (30/9/10)
EU austerity drive country by country BBC News (30/9/10)
Anglo-Irish was ‘systemic threat’ BBC News (30/9/10)
Questions
- What do we mean by government borrowing?
- With such high levels of government debt, what would you expect to happen to interest rates on government debt? Explain your answer.
- When deciding whether or not to bail out the banks, what process could a government use?
- The Irish Finance Minister talks about the institutions becoming a ‘systemic threat’. What does he mean by this?
- Why might the UK economy suffer from the problems in Ireland?
- To what extent do you agree that there is a two-speed Europe, with the core economies, such as France and Germany making good economic progress, but the peripheral economies still suffering from the effects of recession?
- How might the situation in Ireland affect other members of Europe? Will there be an impact on the euro exchange rate?
From the end of January to the beginning of March, the sterling exchange rate index fell by over 6% – from 81.7 to 76.5. Against the dollar, the fall has been even more dramatic, falling from $1.62 to $1.49 (a fall of 8%). What are the reason for this? And is the depreciation likely to continue? The following clip looks at what has been going on and whether the reasons are political, or whether there are other economic fundamentals that have contributed to sterling’s fall.
Stephanie Flanders on the pound BBC Politics Show, Jo Coburn and Stephanie Flanders (2/3/10)
Articles
One-way bet? BBC News blogs: Stephanomics, Stephanie Flanders (1/3/10)
Euro drops to lowest level in 10 months against dollar BBC News (2/3/10)
Fiscal and political fears hit sterling Financial Times, Peter Garnham (1/3/10)
Sterling’s slide is not just about polls Financial Times (2/3/10)
Sterling rout is more than a wobble over political uncertainty Guardian, Larry Elliott (1/3/10)
The pound is weighed down Guardian, Howard Davies (2/3/10)
Sterling jitters The Economist (1/3/10)
Sterling crisis might break Britain’s political and economic paralysis Telegraph, Jeremy Warner (3/3/10)
Questions
- What are the reasons for the depreciation of sterling between January and March 2010?
- Why was selling sterling a ‘one-way bet’ for speculators?
- Why might there have been ‘overshooting’ of the sterling exchange rate?
- Who gain and who lose from a depreciation of sterling?
- What is the likely effect of a depreciation of sterling on (a) inflation; (b) economic growth; (c) interest rates? Explain your answers.
- How do problems of government debt affect countries’ exchange rates?
Northern Rock seems to have had a fixed place in the news for the past year or so. Unfortunately, the advertising it’s been getting hasn’t been positive. The usual picture was one of a Northern Rock branch and a few hundred people queuing outside, ready to withdraw their savings.
In the financial crisis, the banking sector has been at the forefront of economic policy and billions of pounds of public money have been invested in banks simply to keep them afloat and encourage them to keep lending. But now the government, in a measure approved by the European Commission, is considering selliing part of Northern Rock, by splitting it into a ‘good bank’, which will be returned to the private sector, and a ‘bad bank’, which will have to remain nationalised. This bad bank would gradually run down its assets and eventually be liquidated. Similar plans are being considered for the part-nationalised Royal Bank of Scotland and Lloyds Banking Group.
Northern Rock’s loan book will be cut from £100bn pre-crisis to just £20bn to ensure that a bank which enjoyed state support should not have “an unfair competitive advantage”. Savers with Northern Rock will find themselves in the ‘good’ bank, while mortgage customers with arrears and those who are regarded as risky, will be seen as ‘bad’ bank clients.
The buyers of these banks remain unknown. Tesco was considered to be a possible buyer of Northern Rock but has pulled out, with plans to build a new full-service bank itself. Established banks, such as Barclays, will not be allowed to make a purchase and the FSA has stated that standards will not be dropped to allow new competitors to enter the market, especially given that much of the banking crisis is due to poor standards and insufficient regulation. National Australia Bank, the owners of Yorkshire and Clydesdale, is a possible buyer, as too is Virgin Money, even though it would require new finance and possibly new partners. Some potential bidders may be ruled out by competition considerations. So let the games begin!
The following articles look at the banking situation and the possible developments.
Where Gordon Brown feared to tread, Kroes is ready to trample Telegraph, Alistair Osborne (28/10/09)
Lloyds eyes capital raising plans BBC News (29/10/09)
Tesco rules out Northern Rock takeover Guardian, Julia Finch (28/10/09)
EU approves Northern Rock split BBC News (28/10/09)
The Business Podcast: The break-up of Northern Rock Guardian (28/10/09)
Lloyds Banking share price could scupper offer SME Web, Roberta Murray (29/10/09)
Roll up, roll up, for the great bank sell off Independent, Richard Northedge (8/11/09)
Treasury says Northern Rock may lose savers as Government pulls out The Times, Francis Elliott and Suzy Jagger (5/11/09)
Union fears for 25,000 jobs as EU insists Lloyds and RBS must shed branches Guardian, Jill Treanor (3/11/09)
Decision time for Lloyds shareholders BBC News, Money Talk, Justin Urquhart Stewart (11/11/09)
The Business podcast: The break-up of Northern Rock Guardian (28/10/09)
Details of the European Commission ruling on the restructuring of Northern Rock can be found at:
State aid: Commission approves restructuring package for Northern Rock
Questions
- What started all the trouble at Northern Rock?
- What are the arguments (a) for and (b) against the break up of Northern Rock and the other banks that received state aid? Do you think the right decision has been made?
- The BBC News article ‘Lloyds eyes capital raising plans’ refers to 43% of Lloyds being owned by the tax payer. What does this mean and how has it happened?
- Why do you think Tesco has decided not to put in a bid to take over Northern Rock?
- Consider the potential bidders for these new ‘good’ and ‘bad’ banks. In each case, consider the (a) advantages and (b) disadvantages. Then, explain the type of take-over or merger this would be and whether there could be any competition considerations.
- One of the aims of recent developments in the banking sector is to increase competition. Why is this so important and how will it affect consumers and businesses?
The pound is regarded as an international currency. However, the financial crisis has caused the value of the pound to fall, reaching a four-month low against the euro in September. This recent weakening of sterling is partly the result of worries that the Lloyds Banking Group will find it difficult to meet the ‘strict criteria to leave the government’s insurance scheme for toxic banking assets’ set for it by the Financial Services Authority.
However, one of the main reasons relates to recently published figures showing UK debt (see for data). The UK’s public-sector net borrowing has now reached £16.1bn and the government’s overall debt now stands at £804.8bn: 57.5% of GDP. This represents an increase of £172bn in the past year. Over the longer term, this is unsustainable. The government could find it increasingly difficult to service this debt. This would mean that higher interest rates would have to be offered to attract people to lend to the government (e.g. through bonds and bills), but this, in turn, would further increase the cost of servicing the debt. Worries about the potential unsustainability of UK govenrment debt have weakened the pound.
But isn’t a lower exchange rate a good thing in times of recession as it gives UK-based companies a competitive advantage over companies abroad? The following articles consider UK debt and the exchange rate.
Pound plumbs five-month euro low BBC News (21/9/09)
Market data Telegraph (22/9/09)
Pound slides back against dollar and euro Guardian (21/9/09)
Pound drops as UK stocks fall for first time in seven days Bloomberg (21/9/09)
Public sector borrowing soaring BBC News (18/9/09)
Govt spending cuts ‘could help pound’ Just the Flight (21/9/09)
Pound dips to four month euro low BBC News (18/9/09)
Weak pound hits eurozone holidaymakers Compare and save (21/9/09)
Questions
- What is the relationship between public debt and the value of the pound? How do interest rates play a part?
- What is quantitative easing and has it been effective? How does it affect the exchange rate?
- What are the advantages and disadvantages of a freely floating exchange rate relative to a fixed exchange rate?
- If the UK had joined the euro, do you think the country would have fared better during the recession? Consider public debt levels: would they have been restricted? What would have happened to interest rates? What would have happened to the rate of recovery