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!
Podcast
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
Questions
- Explain the difference between induction and abduction.
- Identify the various ‘threshold concepts’ in economics. Does an understanding of these concepts help an economist do better detective work?
- How might forensic economics be used for crime fighting?
- Why might elegant and sophisticated economic theory be dangerous in the ‘messy’ and statistically ‘noisy’ real world?
- In trying to establish an explanation for “100 Million Missing Women”, what use was made of abduction, induction and deduction?
A recent article on this blog discussed the likelihood that we will soon move to a cashless society. It is therefore interesting to consider the implications that this might have for consumer behaviour. We might expect the form of payment to make no difference to a rational consumer. However, there is considerable evidence to suggest that this is not the case.
One reason why people appear to spend more freely on credit cards is payment decoupling – you get utility from the item purchased before you pay the cost. However, more recent evidence suggests that this is not the only relevant factor. It appears that the degree of transparency of the payment method also has an effect. Psychologists quoted in the above article conclude from their experimental evidence that:
Payment modes differ in the transparency with which individuals can feel the outflow of money. ….with cash being the most transparent payment mode.
This effect also appears to make people spend cash less freely.
The author of the above article spent some time experimenting with trying to make all his purchases using cash. He found that by doing so, he was able to reduce his spending by about 10%. However, this seems likely to become harder to do in the future and, as the article concludes, it is already difficult to purchase some items with cash.
Article
Why does foreign money seem like play money? Science Codex (04/06/07)
Questions
- What type of products is it already difficult to purchase with cash?
- How did the psychologists test the transparency of payment methods?
- Do you think the consumer behaviour described above is likely to persist in the long-run?
- Might firms be able to take advantage of the consumers behave described above?
- Do you think the transparency of foreign currencies is the main reason why people spend more when they are abroad?
With the deepening euro crisis, the slide back into recession in many developed countries and the slowing down of fast-growing developing countries, such as China and India, confidence is waning.
But just as pessimism increases, so too does uncertainty. The global economy is getting more and more difficult to forecast. So should economists give up trying to forecast? Should we rely on guesswork and hunch, or looking into crystal balls?
Bank of England representatives have been appearing before the Treasury Select Committee. And they have reiterated the consensus that things are getting more difficult to forecast. As Mervyn King said in his evidence:
There is just enormous uncertainty out there. I have no idea what is going to happen in the euro area.
And this uncertainty is making people cautious, which, in turn, damages recovery. As Dr King went on to say:
There is no doubt that with the additional uncertainty this year there’s evidence of people behaving in a very defensive way, being unwilling to invest and of course the most extreme example of that would be if we were to get to a liquidity trap where essentially the main assets people wanted to hold were claims on the central bank.
Part of the reason for the uncertainty about global growth prospects is uncertainty about what European leaders will decide about the future of the eurozone. Another is uncertainty about how people will respond to the uncertainty of others. But predicting how others will predict is very difficult as they will themselves be predicting what others will predict. This dilemma was observed by Keynes when observing how investors on the stock market behaved, all trying to predict what others will do, and is known as the Keynesian Beauty Contest dilemma (see also).
So are governments and central banks powerless to counteract the uncertainty and pessimism? Can they restore confidence and growth? Members of the Bank of England’s Monetary Policy Committee believe that further action can be taken to stimulate aggregate demand. Further quantitative easing and cuts in interest rates could help as, according to Dr King, we are not yet in a liquidity trap.
UK Economic Outlook Uncertain Amid Euro Zone Crisis – BOE NASDAQ, Ilona Billington (26/6/12)
BOE King: UK Not In Liquidity Trap; No Limit On QE Market News International (26/6/12)
BOE King: Unity On Loose Policy; Not Half Way Through Crisis Market News International (26/6/12)
Full Text Of BOE MPC Dale At Treasury Select Committee Market News International (26/6/12)
Recovery still five years away, Mervyn King warns The Telegraph, Philip Aldrick (26/6/12)
Governor pessimistic on recovery ShareCast, Michael Millar (26/6/12)
Bank’s King says ‘pessimistic’ about worsening economy BBC News (26/6/12)
UK economic outlook getting worse, warns Bank of England Guardian, Phillip Inman (26/6/12)
Questions
- Why is it worth economists forecasting, even if those forecasts rarely turn out to be totally accurate?
- Why is it particularly difficult in current circumstances to forecast the state of the macroeconomy 12 months hence – let alone in two or three years?
- In what ways is the global macroeconomic situation deteriorating? What can national governments do about it?
- What limits the effectiveness of government action to deal with the current situation?
- What is meant by the liquidity trap? Are we close to being in such a situation today?
- Explain what is meant by the Keynesian Beauty Contest? How is this relevant today in explaining economic uncertainty and the difficulty of forecasting the economy?
A key economic principle is that rational decision making requires thinking at the margin. This involves a comparison of the additional (or marginal) benefits and costs of an activity.
An example of such rational behaviour would be deciding to drink one more beer or spending one more hour studying only if the additional benefits were greater than the additional costs. The optimum is where marginal benefit equals marginal cost.
And this applies to firms too. A firm maximises its profits by producing the output at which marginal revenue is equal to marginal cost.
However, a recent book by the American business guru Clayton Christensen argues that thinking in this way can be a problem. A recent article in the Guardian describes a story he tells of the time he refused to play for his university basketball team in a national final which took place on a Sunday and therefore conflicted with his religious beliefs. His decision involved sticking to his principles rather than thinking at the margin. For him, whilst the marginal cost of sacrificing these principles just once may well have been small compared to the resulting benefits, the eventual cost would be much higher.
Christensen also suggests that similar arguments can apply to firm decision making. The above article provides an example he uses of decisions made by executives at the Blockbuster video chain. When smaller rivals started offering movies by mail, Blockbuster instead continued to invest in its existing video store business model. This eventually proved disastrous for the company. The explanation given for this is that building on previous investments made more sense than setting up a mail-order arm which would cannibalise their existing business. On the other hand, an alternative explanation may be that executives at Blockbuster were irrationally allowing sunk costs to affect their decision making.
Articles
Clayton Christensen’s “How Will You Measure Your Life?” Harvard Business School, Clayton Christensen (9/5/12)
Clay Christensen’s life lessons BloombergBusinessweek, Bradford Wieners (3/5/12)
Bust Blockbuster goes on the block Guardian, Ben Child (4/4/11)
Questions
- Can you think of a situation where you have decided to stick to your principles rather than think at the margin?
- Why does a firm maximise profit by producing the output at which marginal revenue is equal to marginal cost?
- What do you think are the main costs of setting up a mail-order business?
- Are these costs mainly fixed or variable costs?
- Why is it irrational to take sunk costs into account when making a decision?
- Can you think of a situation where you have been influenced by sunk costs?
Will we soon live in a world without cash? More and more payments are being made electronically: whether by credit card or debit card, or by direct debit or bank transfer, or by cash loaded cards. For many people cash is now largely used only for small transactions.
But even here, things are changing. Direct transfers via mobile phone apps are increasingly being used for small transactions. Mobile phone companies, banks and others are busy developing such apps and more and more are being released onto the market.
And it’s not just in developed countries. Many developing countries are finding that mobile phones are an ideal way of transferring money for a whole range of transactions. For example, in Kenya, under 20% have a formal bank account, only 1% have a landline and yet more than 70% have a mobile phone, and this percentage is still rising. In 2007, a system known as M-Pesa (see also) was launched:
The user can create a free account and deposit money into it for free with registered agents at retail outlets. They may be gas stations, supermarkets, banks or micro-finance providers or small and medium-sized businesses. No minimum account balance is required.
The user can then transfer up to $440 from the account to someone else — including someone who doesn’t have a cellphone. The recipient provides identification and picks up the cash from another registered agent.
Users can deposit and withdraw cash, pay water and electricity bills, pay their children’s school fees, get paid by their employers or buy extra airtime for their phone.
Other developing countries are introducing similar systems. The second webcast link below gives an example from South Africa.
So how long will it be before cash disappears as a medium of exchange? Or will people continue to prefer to carry cash around with them – especially given the convenience of having cash machines readily available which do not charge for use.
Webcasts
Life in a cashless society BBC News Magazine, David Wolman (14/6/12)
FNB Introduces Cashless Payment App ABNDigital on YouTube (14/5/12) (see also FNB launches new geo-payment system IT News, Africa
PayPal leads mobile payments push Reuters (4/6/12)
Are We Moving Towards a Cashless Society? TheAlyonaShow on YouTube (14/3/12)
Articles
More than 70 per cent of Canadians ready to go “cashless” CNW (13/6/12)
Is a cashless society on the way? Westfair Online, Janice Kirkel (18/5/12)
Mobile money misery BBC News, Rory Cellan-Jones (16/5/12)
Cellphones transform Kenyan commerce CBC News (27/10/10)
Chart

For a PowerPoint of the above chart, click here.
Questions
- What are the advantages and disadvantages of using cash?
- To what extent can mobile phone technology replace cash? What are the advantages and disadvantages of such technology?
- To what extent can mobile phone technology fulfil the various functions of money?
- Private-sector holdings of cash have been rising as a proportion of (nominal) GDP – see above chart. Is this consistent with a decreased use of cash? Explain.
- Why may mobile phone transactions be particularly useful in developing countries?
- What proportion of your own expenditure is conducted by cash? Has this changed over the past couple of years? If so, explain why.