Category: Essentials of Economics: Ch 02

Food prices often rise or fall with good or bad harvests or because of a change in demand. A recent example is the price of brazil nuts, which by May this year had risen over 60% on European markets.

Part of the reason for the price rise has been on the demand side. Consumption of brazil nuts has increased as more people switch to healthier diets. This includes the purchase of the nuts themselves and as part of healthier snack foods. With supply being relatively inelastic, any rise in demand tends to have a relatively large effect on price.

A more acute reason is on the supply side. There has been a very poor harvest of brazil nuts. The nuts are grown largely in the Amazon basin which has been hit by drought linked to the El Niño effect. This, however, is only a temporary effect and future harvests should increase again as rainfall returns to normal. However, in the longer term, rainfall patterns may change with the effects of global warming.

The price rise in the UK has also be aggravated by the depreciation of the pound since the Brexit vote, which has fallen some 13% against the dollar since June 2016. A rise in the dollar price of brazil nuts has thus led to an even bigger rise in their sterling price.


Brazil nuts are rocketing in price – here’s why The Conversation, Iain Fraser (24/10/17)
Brazil nut prices soaring due to reduced harvests after droughts Independent, Zlata Rodianova (16/5/17)


Index Mundi commodities Linked from Economics Network site
Commodity Markets World Bank (see Excel file of monthly prices)


  1. Explain the specific supply conditions that have affected the price of brazil nuts in 2017.
  2. Why did prices rise ahead of the change in supply?
  3. How has the size of the price rise been affected by the price elasticity of demand for brazil nuts?
  4. What determines the price elasticity of demand for brazil nuts?
  5. Find out what other food prices have risen or fallen a lot in recent months and explain why.
  6. How do real food prices (i.e. prices after correcting for inflation) compare today with 10 and 20 years ago? Explain why.

Thirty years ago, on Monday 19 October 1987, stock markets around the world tumbled. The day has been dubbed ‘Black Monday’. Wall Street fell by 22% – its biggest ever one-day fall. The FTSE 100 fell by 10.8% and by a further 12.2% the next day.

The crash caught most people totally by surprise and has never been fully explained. The most likely cause was an excessive rise in the previous three years, when share prices more than doubled. This was combined with the lack of ‘circuit breakers’, which today would prevent excessive selling, and a ‘herd’ effect as people rushed to get out of shares before they fell any further, creating a massive wave of destabilising speculation.

Within a few weeks, share prices started rising again and within three years shares were once again trading at levels before Black Monday.

Looking back to the events of 30 years ago, the question many fund managers and others are asking is whether global stock markets are in for another dramatic downward correction. But there is no consensus of opinion about the answer.

Those predicting a downward correction – possibly dramatic – point to the fact that stock markets, apart from a dip in mid-2016, have experienced several years of growth, with yields now similar to those in 1987. Price/earnings ratios, at around 18, are high relative to historical averages.

What is more, the huge increases in money supply from quantitative easing, which helped to inflate share prices, are coming to an end. The USA ceased its programme three years ago and the ECB is considering winding down its programme.

Also, once a downward correction starts, destabilising speculation is likely to kick in, with people selling shares before they go any lower. This could be significantly aggravated by the rise of electronic markets with computerised high-frequency trading.

However, people predicting that there will be little or no downward correction, and even a continuing bull market, point to differences between now and 1987. First, the alternatives to shares look much less attractive than then. Bond yields and interest rates in banks (at close to zero), unlike in 1987, are much lower than the dividend yields on shares (at around 4%). Second, there are circuit breakers in stock markets that suspend dealing in cases of large falls.

But even if there is a downward correction, it will probably be relatively short-lived, with the upward trend in share prices continuing over the long term. If you look at the chart above, you can see this trend, but you can also see periods of falling share prices in the late 1990s/early 2000s and in the financial crisis of 2008–9. Looking back to 1987, it seems like a mere blip from the perspective of 30 years – but it certainly didn’t at the time.


Three decades since Black Monday – are markets on the verge of another tumble? The Telegraph, Lucy Burton (19/10/17)
Black Monday: 30 years on from the 1987 crash Citywire, Michelle McGagh (19/10/17)
30 Years Ago: Lessons From the 1987 Market Crash U.S.News, Debbie Carlson (12/10/17)
Black Monday: Can a 1987-style stock market crash happen again? USA Today, Adam Shell (19/10/17)
Black Monday anniversary: How the 2017 stock market compares with 1987 MarketWatch, William Watts (19/10/17)
30 years after Black Monday, could stock market crash again? MarketWatch, William Watts (19/10/17)
The Crash of ’87, From the Wall Street Players Who Lived It Bloomberg, Richard Dewey (19/10/17)


  1. Explain what are meant by ‘bull markets’ and ‘bear markets’.
  2. Share prices are determined by demand and supply. Identify the various demand- and supply-side factors that have led to the current long bull-market run.
  3. What caused the Black Monday crash in 1987?
  4. For what reasons may global stock markets soon (a) experience, (b) not experience a downward correction?
  5. Distinguish between stabilising speculation and destabilising speculation on stock markets.
  6. What determines when a downward correction on stock markets bottoms out?
  7. Explain how stock market circuit breakers work. Can they prevent a fundamental correction?
  8. Does the rise in computerised trading make a stock market crash more or less likely?

The annual Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel, normally known as the Nobel Prize in Economics, has been awarded 49 times since it was founded in 1969. Many well-known economists have been recipients of the award. This year it had been awarded to Richard Thaler for his research in behavioural economics. The award recognises his work in integrating economics with psychology.

Richard H. Thaler has incorporated psychologically realistic assumptions into analyses of economic decision-making. By exploring the consequences of limited rationality, social preferences, and lack of self-control, he has shown how these human traits systematically affect individual decisions as well as market outcomes.

In total, Richard Thaler’s contributions have built a bridge between the economic and psychological analyses of individual decision-making. His empirical findings and theoretical insights have been instrumental in creating the new and rapidly expanding field of behavioural economics, which has had a profound impact on many areas of economic research and policy.

Instead of making the assumption that people are rational maximisers, behavioural economists look at how people actually behave and respond to various incentives.

For example, people may be motivated by concepts of fairness and be prepared to make personal sacrifices for the sake of others. Such concepts of fairness tend to depend on the social context in which choices are made and can be influenced by the way choices are framed.

Also people may not weigh up costs and benefits but use simple rules of thumb, or heuristics, when making decisions. This might be an example of rational behaviour when time or information is limited, but the use of such heuristics often becomes engrained in behaviour and the rules become just habit.

People may also suffer from a lack of willpower or ‘present bias’. They may spend more than they can afford because they cannot resist the temptation to have a product. They may overeat because of the short-term pleasure it brings and ignore the long-term effects on their health.

Understanding how people make choices and the temptations to which they succumb can help policymakers devise incentives to change behaviour to achieve various social goals.

One type of incentive is nudging. A well-known example is people’s choice about whether to become an organ donor in the event of their death. If people are required to opt in to such a scheme, they may never get round to doing so. However, if they are required to opt out if they do not want to participate, many more people would thereby be donors and more organs would become available.

Another form of nudge is making desirable things fun. A well-known experiment here was encouraging people to use the stairs rather than the escalator when exiting a subway by making the stairs like a musical keyboard. See here for more examples.

The UK government set up a Behavioural Insights Team – also known as the Nudge Unit (now independent of government) to find ways of encouraging people to behave in their own or society’s best interests.

But it is not just governments which use the insights of behavioural economists such as Thaler. The advertising and marketing industry is always examining the most effective means of influencing behaviour. A classic example is the loss leader, where consumers are tempted into a shop with a special offer and then end up buying more expensive items there rather than elsewhere.

Firms and advertisers know only too well the gains from tempting people to buy items that give them short-term gratification – such as putting chocolate bars by the tills in supermarkets.

Understanding consumer psychology helps firms to manipulate people’s choices. And such manipulation may not be in our best interests. If we are being persuaded to buy this product or that, are we fully aware of what’s going on and how our tastes are being affected? Would we, by standing back and reflecting, make the same choices as we do on impulse or out of habit?

And governments too can seek to manipulate people in ways that some may find undesirable. Governments may try to influence us to follow their particular political agenda – as may newspapers. Certainly, during election or referendum campaigns, we are being nudged to vote a particular way.

It is important then for us to understand when we are being nudged or otherwise persuaded. Do we really want to behave in that way? Just as it is important, then, for governments and firms to understand individuals’ behaviour, so too it is important for individuals to understand their own behaviour.


Richard Thaler’s work demonstrates why economics is hard The Economist, RA (11/10/17)
Nobel in Economics Is Awarded to Richard Thaler The New York Times, Binyamin Appelbaum (9/10/17)
The Making of Richard Thaler’s Economics Nobel The New Yorker, John Cassidy (10/10/17)
Nobel prize in economics awarded to Richard Thaler The Guardian, Richard Partington (10/10/17)
Richard Thaler is a controversial Nobel prize winner – but a deserving one The Guardian, Robert Shiller (11/10/17)
What the mainstreaming of behavioural nudges reveals about neoliberal government The Conversation, Rupert Alcock (17/10/17)
This year’s economics Nobel winner invented a tool that’s both brilliant and undemocratic Vox, Henry Farrell (16/10/17)
How a critic of economics became the disciplines Nobel-winning best friend The Guardian, Tiago Mata and Jack Wright (25/10/17)


How Richard Thaler changed economics BBC, More of Less, Tim Harford (14/10/17)


  1. For what reasons may individuals not always weigh up the costs and benefits of purchasing an item?
  2. Give some examples of the use of heuristics in making consumption decisions?
  3. Is the use of heuristics irrational?
  4. Explain how people considering that they have behaved fairly is influenced by the social context of their behaviour?
  5. Find out what is meant by the Dictator Game and how it can challenge the assumption that people behave selfishly. How is the ‘dictator’s’ behaviour affected by the possible payoffs?
  6. Thaler suggested that Brexit could be an example of behavioural economics in action. Find out what he meant by this. Do you agree?
  7. Give some examples of ways in which the government can nudge people to persuade them to behave in socially or individually desirable ways.
  8. Find out what is meant by the ‘endowment effect’ and how it influences people’s valuation of items they own.
  9. Why may nudging by governments be undemocratic?

Oil prices are determined by demand and supply. Changes in oil prices are the result of shifts in demand and/or supply, with the size of the price change depending on the size of the shift and the price elasticity of demand and supply.

Some of the shifts are long term, with the price of oil varying from year to year or even moving in a particular direction for longer periods of time. Thus the opening up of new supplies, such as from fracking wells, can lead to a long-term fall in oil prices, while agreements by, say, OPEC to curb output can lead to a long-term rise in prices (see the blogs The oil see-saw, OPEC deal pushes up oil prices and An oil glut).

Medium and long-term price movements can also reflect medium and long-term changes in demand, such as a recession – oil prices fell dramatically as the world economy slid into recession in 2008/9 and then recovered as the global economy recovered.

Another long-term factor is the development of substitutes, such as renewable energy, which can reduce the demand for oil; another is developments that economise on power, such as more fuel-efficient vehicles and machines.

But oil prices do not just reflect these long-term movements in demand and supply. They also reflect daily and weekly movements as demand and supply respond to global and national events.

Two such events occurred at the end of August/beginning of September this year. The first was Hurricane Harvey. Even though it was downgraded to a tropical storm as it made landfall across the coast of the Gulf of Mexico, it dumped massive amounts of rain on southern Texas and Louisiana. This disrupted oil drilling and refining, shutting down a quarter of the entire US refining capacity. The initial effect was a surge in US oil prices in late August as oil production in much of Texas shut down and a rise in petrol prices as supplies from refineries fell.

Then prices fell back again in early September as production and refining resumed and as it became apparent that there had been less damage to oil infrastructure than initially feared. Also the USA tapped into some of its strategic oil reserves to make up for the shortfall in supply.

Then in early September, the North Koreans tested a hydrogen bomb – much larger than the previous atom bombs it had tested. This prompted fears of US retaliation and heightened tensions in the region. As the Reuters article states:

That put downward pressure on crude as traders moved money out of oil – seen as high-risk markets – into gold futures, traditionally viewed as a safe haven for investors. Spot gold prices rose for a third day, gaining 0.9 per cent on Monday

Quite large daily movements in oil prices are not uncommon as traders respond to such events. A major determinant of short-term demand is expectations, and nervousness about events can put substantial downward pressure on oil prices if it is felt that there could be a downward effect on the global economy – or substantial upward pressure if it is felt that supplies might be disrupted. Often markets over-correct, with prices moving back again as the situation becomes clearer and as nervousness subsides.


U.S. crude edges higher, gasoline tumbles after Harvey Reuters, Libby George (4/9/17)
Global oil prices fall after North Korea nuclear weapon test Independent, Henning Gloystein (4/9/17)
Brent crude oil falls after North Korea nuclear test The Indian Express (4/9/17)
Oil prices remain volatile AzerNews, Sara Israfilbayova (4/7/17)


  1. What are the determinants of the price elasticity of demand for oil?
  2. Search news articles to find some other examples of short-term movements in oil prices as markets responded to some political or natural event.
  3. Why do markets often over-correct?
  4. Explain the long-term oil price movements over the past 10 years.
  5. Why is gold seen as a ‘safe haven’?
  6. If refineries buy oil from oil producers, what would determine the net effect on oil prices of a decline in oil production and a decline in demand for oil by the refineries?
  7. What role does speculation play in determining oil prices? Explain how such speculation could (a) reduce price volatility; (b) increase price volatility. Under what circumstances is (b) more likely than (a)?

According to the Halifax house price index, house prices fell in the UK in the three months to April. This is the first quarterly fall since 2012. The Nationwide index (see below), shows that prices in April were 0.4% lower than in March (although the 3-month rate was still slightly positive).

The fall in house prices reflects a cooling in demand. This, in turn, reflects a squeeze on household incomes as price rises begin to overtake wage rises. It also reflects buyers becoming more cautious given the uncertainty over the nature of the Brexit deal and its effects on the economy and people’s incomes.

The fall in demand is also driven by recent Bank of England rules which require mortgage lenders to limit the proportion of mortgages with a mortgage/income ratio of 4.5 or above to no more than 15% of their new mortgages. It is also affected by a rise in stamp duty, especially on buy-to-let properties.

Despite the fall in prices, this may understate the fall in demand relative to supply. House price movements often lag behind changes in demand and supply as people are reluctant to adjust to equilibrium prices. In the case of a falling market, sellers may be unwilling to sell at the lower equilibrium price, believing that a lower price ‘undervalues’ their property. Indeed, they may not even put their houses on the market. This makes prices ‘sticky’ downwards. The result is a fall in sales.

Eventually, such people will reluctantly be prepared to accept a lower price and prices will thus fall more. Once people come to expect price falls, supply may increase further as vendors seek to sell before the price falls even more. So we could well see further falls over the coming months.

Lower house prices and falling sales is a picture repeated in many parts of the UK. It is particularly marked in central London. There, estate agents have begun to offer free gifts to purchasers. As The Guardian puts it:

London estate agents have begun to offer free cars worth £18,000, stamp duty subsidies of £150,000, plus free iPads and Sonos sound systems to kickstart sales in the capital’s increasingly moribund property market. The once super-hot central London market has turned into a ‘burnt-out core’ according to buying agents Garrington Property Finders, prompting developers to offer ever greater incentives to lure buyers.

… Land Registry figures show that in the heart of the city’s financial district, average property prices plummeted from £861,000 at the time of the EU referendum to £773,000 in February, a decline of 15%, although in London’s outer boroughs prices are still up over the year.

But lower property prices are good news for first-time buyers, although some of the biggest falls have been in the top end of the market.

The fall in property prices may continue for a few months. But population is rising, and with it the number of people who would like to buy their own home. Once real incomes begin to rise again, therefore, demand is likely to resume rising faster than supply. When it does, house prices will continue their upward trend.


UK house prices in first quarterly fall since 2012 BBC News (8/5/17)
UK house prices fall again in April as buyers feel the pinch The Guardian, Angela Monaghan (28/4/17)
Buy a home, get a car free: offers galore as London estate agents struggle to sell The Guardian, Patrick Collinson (3/5/17)
London is now one of the five cities with the lowest house price growth in the UK City A.M., Helen Cahill (28/4/17)
London Housing Market Property Bubble Vulnerable To Crash The Market Oracle, Jan Skoyles (3/5/17)
A key indicator of a healthy housing market is flashing red in London Business Insider, Thomas Colson (29/5/17)

House Price Data
UK House Prices – links to various sites Economic Data freely available online – Economics Network


  1. Why are UK house prices falling?
  2. What determines the rate at which they are falling? How is the price elasticity of demand and/or supply relevant here?
  3. How does speculation help to explain changes in house prices? How may speculation help to (a) stabilise and (b) destabilise house prices?
  4. Draw a demand and supply diagram to show how house transactions will be lower if the market is not in equailibrium.
  5. Why are house prices falling faster in central London than elsewhere in the UK?
  6. Why are rents falling in central London? How does this relate to the fall in central London property prices?
  7. How has the Help to Buy scheme affected house prices? Has it affected both demand and supply and, if so, why and how?
  8. How do changes in residential property transaction volumes relate to changes in property prices?
  9. What market imperfections exist in the housing market?