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Posts Tagged ‘assumptions’

As UK inflation rises, so real wages begin to fall

With the effects of the depreciation of sterling feeding through into higher prices, so the rate of inflation has risen. The latest figures from the ONS show that in the year to April 2017, CPI inflation was 2.7% – up from 2.3% in the year to March. The largest contributors to higher prices were transport costs and housing and household services.

But wage increases are not keeping up with price increases. In 2017 Q1, the average annual growth rate in regular pay (i.e. excluding bonuses) was 2.1%. In other words, real pay is falling. And this is despite the fact that the unemployment rate, at 4.6%, is the lowest since 1975.

The fall in real wages is likely to act as a brake on consumption and the resulting dampening of aggregate demand could result in lower economic growth. On the other hand, the more buoyant world economy, plus the lower sterling exchange rate is helping to boost exports and investment and this could go some way to offsetting the effects on consumption. As Mark Carney stated in his introductory remarks to the May 2017 Bank of England Inflation Report:

The combination of the stronger global outlook and sterling’s past depreciation is likely to support UK net trade. And together with somewhat lower uncertainty, stronger global growth is also likely to encourage investment as exporters renew and increase capacity.

According to the Bank of England, the net effect will be modest economic growth, despite the fall in real wages.

In the MPC’s central forecast, quarterly growth is forecast to stabilise around its current rate, resulting in growth of 1.9% in 2017 and around 1¾% in each of the next two years.

But forecasting is dependent on a range of assumptions, not least of which are assumptions about consumer and business expectations. These, in turn, depend on a whole range of factors, such as the outcome of the UK election, the Brexit negotiations, commodity prices, world growth rates and international events, such as the actions of Donald Trump. Because of the uncertainty surrounding forecasts, the Bank of England uses fan charts. In the two fan charts illustrated below (from the May 2017 Inflation Report), the bands on constructed on the following assumptions:

If economic circumstances identical to today’s were to prevail on 100 occasions, the MPC’s best collective judgement is that CPI inflation or the mature estimate of GDP growth would lie within the darkest central band on only 30 of those occasions and within each pair of the lighter coloured areas on 30 occasions.

The charts and tables showing the May 2017 projections have been conditioned on the assumptions that the stock of purchased gilts remains at £435 billion and the stock of purchased corporate bonds remains at £10 billion throughout the forecast period, and on the Term Funding Scheme (TFS); all three of which are financed by the issuance of central bank reserves. They have also been conditioned on market interest rates, unless otherwise stated.

The wider the fan, the greater the degree of uncertainty. These fan charts are wide by historical standards, reflecting the particularly uncertain future for the UK economy.

But one thing is clear from the latest data: real incomes are falling. This is likely to dampen consumer spending, but just how much this will impact on aggregate demand over the coming months remains to be seen.

UK real wages drop for first time in three years Financial Times, Sarah O’Connor (17/5/17)
Bank of England warns Brexit vote will damage living standards The Guardian, Katie Allen (11/5/17)
UK wage growth lags inflation for first time since mid-2014 BBC News (17/5/17)
Britons’ Falling Real Wages Show Challenging Times Have Arrived Bloomberg, Scott Hamilton and Lucy Meakin (17/5/17)
Jobs market will suffer a Brexit slowdown, say experts The Guardian, Angela Monaghan and Phillip Inman (15/5/17)
Pay will continue to be squeezed, employers’ survey suggests BBC News, Kamal Ahmed (15/5/17)
Brexit latest: Real wages falling, Office for National Statistics reveals Independent, Ben Chu (17/5/17)
UK inflation climbs to four-year high, beating forecasts Financial Times, Gavin Jackson (16/5/17)
Why is UK inflation at a four-year high? Financial Times, Gavin Jackson (19/5/17)
A blip, or a test of hawks’ patience? Economists respond to high UK inflation data Financial Times, Nicholas Megaw (16/5/17)
UK inflation rate at highest level since September 2013 BBC News (16/5/17)
Inflation jumps to its highest level since 2013 as Brexit continues to bite Business Insider, Will Martin (16/5/17)
UK GDP growth weaker than expected as inflation hits spending The Guardian, Katie Allen (25/5/17)
UK economic growth estimate revised down BBC News (25/5/17)

Inflation Report, May 2017 Bank of England (11/5/17)
Labour Market Outlook, Sping 2017 Chartered Institute of Personnel and Development (May 2017)

Statistical Interactive Database – interest & exchange rates data Bank of England
Inflation and price indices ONS
Earnings and working hours ONS
Second estimate of GDP: Jan to Mar 2017 ONS Statistical Bulletin (25/5/17)


  1. Find out what has happened to the dollar/sterling and the euro/sterling exchange rate and the sterling exchange rate index over the past 24 months. Plot the data on a graph.
  2. Explain the changes in these exchange rates.
  3. Why is there negative real wage growth in the UK when the rate of unemployment is the lowest it’s been for more than 40 years?
  4. Find out what proportion of aggregate demand is accounted for by household consumption. Why is this significant in understanding the likely drivers of economic growth over the coming months?
  5. Why is uncertainty over future UK growth rates relatively high at present?
  6. Why is inflation likely to peak later this year and then fall?
  7. What determines the size and shape of the fan in a fan chart?
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Did you hear the one about Kilkenomics?

The town of Kilkenny in Ireland has just hosted the sixth annual Kilkenomics festival (Nov 5–8) where economics and comedy meet. The festival brought together comedians and economists to take a look at some of the most pressing economic and social issues, such as the refugee crisis, economic recovery, banking and finance, the growth in inequality, the future of the EU, economic power, the environment and personal behaviour.

With stand-up comedians taking a sideways look at economic issues and top economists having their ideas lampooned, or lampooning them themselves, the festival provided a fun, but useful, reality check for the discipline of economics.

The festival attracted some major names in the field of comedy, economics, journalism and politics. Perhaps the biggest draw was the former finance minister of Greece, Yanis Varoufakis (see also), who opened the festival with a withering attack on the economic model being pursued by Greece’s creditors (the European Commission, the IMF and the ECB).

Much of the comedy was really aimed, not so much at economics and economists, but more at how politicians pursue economic policies and interpret economic models in ways that suit their own political agenda. But still there was no escape for economists. Much of the humour was directed at unrealistic assumptions and unrealistic visions of how economies function.

Thanks to JokEc for the following:

 •  Economics is the only field in which two people can get a Nobel Prize for saying exactly the opposite thing.
 •  If you rearrange the letters in “ECONOMICS”, you get “COMIC NOSE”.
 •  Economics has got so rigorous we’ve all got rigor mortis.
 •  How many economists does it take to change a light bulb?

I’ll leave you to work out the best answer to that last one – there could be many depending on the school of thought.

Videos and podcasts
Kilkenomics Promo – 2015 Kilkenomics on YouTube (23/10/15)
Kilkenomics: Highlights 1 Kilkenomics on YouTube (27/10/15)
Kilkenomics: Highlights 2 Kilkenomics on YouTube (30/10/15)
Kilkenomics 2014 BBC ‘In the Balance’ (9/11/14)

Kilkenomics launches biggest programme to date Meath Chronicle (1/10/15)
The subversive wonders of Kilkenomics – where economics meets stand-up The Spectator, Liam Halligan (15/11/14)
Guilty as charged: Irish standup festival puts economics in the dock The Guardian, Larry Elliott (8/11/15)
Ireland no paradigm of successful austerity – Varoufakis The Irish Times, Eoin Burke Kennedy (5/11/15)
Economy of sex … how much are your orgasms costing you? Irish Independent, Niamh Horan (8/11/15)


  1. What is it about economics that gives so much material to comedians?
  2. ‘The worse it gets the funnier it seems because comedy exists with tragedy.’ To what extent is this true of economics as a discipline or simply of the state of the world economists are studying at any one time?
  3. Should assumptions in economics always be realistic? Explain why or why not.
  4. For what types of reason might economists disagree?
  5. Make up an economics joke and test it on your fellow students. Perhaps there ought to be a vote for the funniest and a prize for the winner. What was it about the winning joke that made it the funniest?
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Should studying economics come with a health warning!!?

Many of you reading the articles on this website will be just about to start, or will have just started, studying economics at university. For some of you this will involve building on the knowledge you obtained prior to university, whereas for others it will be the first time you have ever studied the subject before. Will studying economics change the way you behave? Should it come with a health warning?

Can studying economics change the way you think and behave? The subject is often sold to prospective students on the grounds that it can. For example it is stated on the Economics Network’s Why Study Economics? website that

The economic way of thinking can help us make better choices

However, is it possible that studying economics could change people’s behaviour in a way that would be to the detriment of society? Some observers have argued that it can. They have suggested that students might be influenced by some of the assumptions that are made in traditional economic theory.

As social scientists, economists are always trying to analyse human behaviour. However, people vary in many different ways and have very diverse preferences. If we want to build a theory that predicts how people will behave and respond in different situations, then some type of simplifying assumptions are inevitable.

Traditionally one of the key simplifying assumptions that economists have used in their theories of human behaviour is that people make decisions in their own self-interest. There is some debate about exactly what self-interest means. For example it could be argued that giving £10 to charity is acting in your own self-interest if it gives you more pleasure than spending that £10 on yourself. However, in many of the economic theories that you first study in economics a narrow meaning of self-interest tends to be used. This is clearly illustrated by the following quote from Milgrom and Roberts. Referring to economic theory they state that:

It is often assumed that people behave as if they were entirely motivated by narrow, selfish concerns

It is important to make it clear that economists are not assuming that people behave in a selfish manner all of the time. Instead, they are assuming that the people in their theories are acting in a selfish manner. The value of making this assumption is whether the predictions about human behaviour that follow from using it are supported by evidence from the real world.

Some researchers have argued that when people study economic theory built on this assumption it makes them more likely to behave in a selfish way. The evidence for this comes from a range of research papers. Here are some findings:

Economics students were more likely than those studying other subjects to recommend the most expensive plumber to a student society if that plumber offered the student a side payment.

Students took part in an experiment in a computer room where they could either keep the money they had been given or donate it to a public good. On average the economics students kept more of the money.

Economics professors gave less money to charity than professors of other subjects such as psychology and sociology.

Some studies also found that selfish people were more likely to choose economics as a subject to study and became more selfish after they had studied it for some time.

If you are about to begin your study of economics then perhaps you should take care that your behaviour outside the classroom is not being unduly influenced by some of the assumptions you are learning about inside the classroom. On a more practical note perhaps you should avoid sharing a restaurant bill or buying rounds of drinks when in the company of other economists!!!

However on a brighter note, the evidence in these papers can be interpreted in a number of different ways. There are even some studies that found economics students were less selfish than those on other courses.

Re-Post: Does Studying Economics Make You Selfish? The Splintered Mind (21/11/12)
Does studying economics make you more selfish? BBC (22/10/13)
Does Studying Economics Breed Greed? Huffington Post (22/10/13)
The Dismal Education The New York Times (16/12/11)
Does Economics Make You a Bad Person? Conversable Economist (31/3/14)
Economists aren’t all bad FT Magazine (11/4/14)


  1. What is an economic model? Why is it necessary to make simplifying assumptions?
  2. How are economic models judged? How important is it for the assumptions to accurately describe the real world?
  3. Try to find some jokes that have been made about the use of assumptions in economic theory.
  4. Can you think of any alternative explanations for the results found in the research papers referred to in the case?
  5. Try to find a research paper that finds evidence that economics students are less selfish than other students.
  6. What is a public good? Explain why someone with selfish preferences would not contribute to the public good.
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Becoming an economic detective

Many of you reading this will be embarking on an economics degree. During your studies you’ll be developing the skills that economists bring to observing and analysing the world around us and considering the policy options to achieve various social and economic objectives. You’ll be learning how to become an ‘economic detective’ and to do ‘forensic economics’.

Identifying the nature of economic problems; collecting and examining the evidence; using the economist’s ‘toolkit’ of concepts and ideas to make sense of the evidence; looking for explanations; constructing hypotheses and theories; considering what can be done to tackle the problems and prevent them occurring in the future – these are the sorts of things you will be doing; and they involve detective work.

The podcast below looks at the methods of Sherlock Holmes. These are the sorts of methods successful economists use. John Gray identifies three types of reasoning. The first two are probably familiar to you, or soon will be.

1. Induction involves looking at evidence and then using it to construct general theories. So, for example, if you observe on many occasions that when the prices of various goods rise, the quantity demanded falls, you can then hypothesise that whenever the price of a good rises, the quantity demanded will fall; in other words, you induce that price and quantity demanded are inversely related – that demand curves are downward sloping. This is known as the ‘Law of demand’. Induction, of course, is only as good as the evidence. Nevertheless, inductive methods are logical and it can be demonstrated how the theories follow from the evidence.

2. Deduction involves using theories to draw conclusions about specific cases. So, for example, you could use the law of demand to deduce that when the price of a specific good rises, the quantity demanded of that good will fall. You would also assume that nothing else had changed that could influence the demand for the good. In other words, you assume ‘ceteris paribus‘ or ‘other things being equal’. As long as you have not made any logical errors, deduction is foolproof. As John Gray puts it:

Deduction is infallible as long as the premises are true, while induction yields probabilities that can always be falsified by events

But there is a third type of reasoning and this is where the true economic detective comes in. This is known as ‘abduction’. This is the type of logic that is used when evidence is thin or where there are lots of scraps of seemingly contradictory evidence. And this is the type of logic employed so successfully by Sherlock Holmes.

3. Abduction involves making informed guesses or estimates from limited evidence. It is using the scraps of evidence as clues as to what might be really going on. It is how many initial hypotheses are formed. Then the researcher (or detective) will use the clues to search for more evidence that can be used for induction that will yield a more robust theory. The clues may lead to a false trail, but sometimes they may allow the researcher to develop a new theory or amend an existing one. A good researcher will be alert to clues; to seeing patterns in details that might previously have been dismissed or gone unnoticed.

Before the banking crisis of 2007/8 and the subsequent credit crunch and recession in the developed world, many economists were picking up clues and trying to use them to develop a theory of systemic risk in financial markets. They were using the skills of an economic detective to try to discover not only what was currently going on but also what might be the consequences for the future. Some used abduction successfully to predict the impending crisis; most did not.

If you are embarking on an economics degree and will possibly go on to a career as an economist, then part of your training will be as a detective. With good detective skills – looking for clues, seeing connections, identifying what more evidence is required and where to find it, and then using it to provide explanations and policy prescriptions – you could make a very successful and sought-after economist. Being a good economist is not just about learning theories and techniques, although this is vitally important; it’s also about being imaginative and thinking ‘outside the box’. Good luck!

Sherlock Holmes and the Romance of Reason BBC: A Point of View, John Gray (17/8/12) (Click here for a transcript.)

Articles and information
Detective work: forensic economics Business:Life, Tim Harford (2/5/12)
The Search for 100 Million Missing Women Slate, Stephen J. Dubner and Steven D. Levitt (24/5/05)
Abduction Stanford Encyclopedia of Philosophy, Igor Douven (9/2/11)
Abductive reasoning Wikipedia


  1. Explain the difference between induction and abduction.
  2. Identify the various ‘threshold concepts’ in economics. Does an understanding of these concepts help an economist do better detective work?
  3. How might forensic economics be used for crime fighting?
  4. Why might elegant and sophisticated economic theory be dangerous in the ‘messy’ and statistically ‘noisy’ real world?
  5. In trying to establish an explanation for “100 Million Missing Women”, what use was made of abduction, induction and deduction?
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