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 Rogoff 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?
On 5 and 6 April, there was a conference on conscious capitalism in San Francisco. In January, a new book, Conscious Capitalism: Liberating the Heroic Spirit of Business, by John Mackey and Rajendra Sisodia, was published. Many in the business world are enthusiastic about this seemingly new approach to business, which focuses on broader social, environmental and ethical goals, rather than simple profit maximisation.
As the Washington Times review linked to below states:
“Conscious Capitalism” promotes a business culture that embodies “trust, accountability, caring, transparency, integrity, loyalty and egalitarianism.” The management ideal of “Conscious Capitalism” contains four key elements of “decentralization, empowerment, innovation and collaboration.” Above all, this exemplary form of business practice relies on careful attention to four tenets: higher purpose and core values, stakeholder integration, conscious leadership and conscious culture and management.
So how realistic is this vision of caring capitalism? There may be a few inspiring businesspeople, truly committed to improving the interests of the various stakeholders of their business and society more generally, but could it become a model for business in general? And if so, does this require education, monitoring and regulation? Or can a libertarian approach to business generate an environment where conscious and caring capitalists flourish and succeed better than those with a more narrow focus on profit?
The following videos and articles discuss conscious capitalism and the arguments of those, such as John Mackey, founder and co-CEO of Whole Food Market, who advocate it.
Webcasts
Conscious capitalism The Economist, John Mackey (15/3/13)
Conscious Capitalism: Heroes of the Business World Conscious capitalism, April in San Francisco (5/4/13)
It’s Not Corporate Social Responsibility Conscious capitalism, John Mackey (Jan 13)
Articles, reviews and information
Conscious Capitalism: Creating a New Paradigm for Business Whole Planet Foundation, John Mackey
Companies that Practice “Conscious Capitalism” Perform 10x Better Harvard Business Review, Tony Schwartz (4/4/13)
4 Ways to Become a (More) Conscious Capitalist Inc., Francesca Louise Fenzi (8/4/13)
The New Management Paradigm & John Mackey’s Whole Foods Forbes, Steve Denning (5/1/13)
Book Review: ‘Conscious Capitalism’ Washington Times, Anthony j. Sadar (20/3/13)
Book Review: Whole Foods Co-CEO John Mackey’s Conscious Capitalism Huffington Post, Christine Bader (28/1/13)
Chicken Soup for a Davos Soul Wall Street Journal, Alan Murray (16/1/13)
Conscious business Wikipedia
Questions
- What are the features of conscious capitalism?
- Do firms “get the shareholders they deserve”?
- How might firms that are not pursuing conscious capitalism be persuaded to become more conscious and more caring?
- How does conscious capitalism differ from corporate social responsibility?
- What would you understand by “conscious consumers”? How might their behaviour differ from other consumers?
- Why might firms engaging in conscious capitalism become more profitable than firms that have a simple aim of profit maximisation?
- What reforms, both internal within a firm and in the legal environment, does John Mackey advocate? Do you agree with his suggestions? What else do you suggest?
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?
The news in many European countries has been dominated in February by the ‘horse meat scandal’. Small traces of horse meat may be the result of faulty quality control. But the significant amount of horse found in several processed meat products suggest fraud at one or more points in the supply chain from farm to supermarket or other outlet. Indeed several specific suppliers, from abattoirs to processors are facing criminal investigation.
The scandal has put the supply chain under intense scrutiny. Part of the problem is that the supply chain is often very long and complex. As the Guardian article states:
The food and retail industries have become highly concentrated and globalised in recent decades. A handful of key players dominate the beef processing and supermarket sectors across Europe. They have developed very long supply chains, particularly for their economy lines, which enable them to buy the ingredients for processed foods from wherever they are cheapest at any point, depending on exchange rates and prices on the global commodity markets. Networks of brokers, cold stores operators and subcontracted meat cutting plants have emerged to supply rapidly fluctuating orders “just in time”. Management consultants KPMG estimate there are around 450 points at which the integrity of the chain can break down.
Then there is the huge pressure on all parts of the supply chain to reduce costs.
Supermarkets use their market power to drive down the prices of the products they buy from their suppliers and this has a knock-on effect backwards down the supply chain. This pressure has intensified as real wages have fallen and consumers have found their budgets squeezed.
At the same time, beef and other meat prices have been rising as the costs of animal feed have soared. This all puts tremendous pressure on suppliers to add cheaper ingredients. Again to quote the Guardian article:
Manufacturers add other cheap ingredients including water and fat, and use concentrated proteins to bind the water and fat in. They may appear on labels as ‘seasoning’. One of the cheapest sources of these protein additives is pork rind. It is possible that horse hide is now also being used. The widespread adulteration of cheap chicken breast with pig and beef proteins and water has been uncovered in previous scandals. The beef proteins were derived from hydrolysed cattle hides. It is not illegal to use these protein concentrates so long as they are identified correctly to the manufacturer.
It is not surprising that if cheap horse meat becomes available to suppliers, such as from old horses towards the end of their working lives, some processing companies may be tempted to add it fraudulently, stating that it is beef.
The articles look at the issues of long and complex supply chains in the processed food industry and assess why they have evolved into their current form and the difficulties in regulating them.
Horsegate: heed economics of the cold chain The Grocer, Andrew Godley (16/2/13)
Horsemeat scandal: the essential guide The Guardian, Felicity Lawrence (15/2/13)
After the horse has been bolted The Economist (16/2/13)
Slavery, not horse meat, is the real scandal on our doorstep The Telegraph, Fraser Nelson (14/2/13)
Industry must take the reins on food safety Globe and Mail (Canada)Sylvain Charlebois (15/2/13)
Supply chains changed the growth model The Economist, Richard Baldwin (15/8/12)
Supply-chain management The Economist (6/4/09)
Tesco pledges to open up supply chain after horse meat scandal The Telegraph (16/2/13)
Horse meat scandal: Shoppers who buy ‘cheapest food’ at risk The Telegraph, James Quinn, Jason Lewis and Patrick Sawer (16/2/13)
Let Them Eat Horse Bloomberg, Marc Champion (15/2/13)
Scandal shows meat supply chain must be policed heraldscotland (14/2/13)
MPs push for new powers for FSA as officials seize yet more suspect meat Independent, Martin Hickman (13/2/13)
Questions
- Why do supermarkets and their suppliers use long supply chains?
- Explain the concepts of ‘countervailing power’ and ‘monopsony or oligopsony power’? How do they apply in the processed meat supply chain?
- Identify the types of transactions costs in the processed meat industry.
- In what ways do consumers (a) gain and (b) lose from such supply chains?
- Why is the problem of fraud in processed food supply chains likely to have intensified in recent years?
- How have supermarkets reacted to the horse meat scandal? Why has it taken the scandal to make them react in this way?
- To what extent is the problem simply one of inaccurate labelling?
- To what extent is there a principal–agent problem in the processed meat supply chain?