Category Archives: Micro

Game Theory and why we go to a coronavirus lockdown

Michael Cameron posted a nice piece on his blog about this – Sex, Drugs and Economics.

Game theory refers to the decision that a firm/individual makes depends on its assumptions about other firms/individuals. Ultimately this means that individuals will try and calculate the best course of action depending on how others behave. When we were in a Level 2 situation the advise was no mass gatherings, physical distance on public transport, limit non-essential travel etc. Although the announcements of the four levels were made clear on the Saturday it was inevitable that we would be moving to Level 4 very quickly – Wednesday. Being able to police Level 2 would have been near impossible and the risk of community transmission meant that complete lockdown was needed.

In a Level 2 situation, which was somewhat voluntary, people had two choices – Stay home (cooperate) or Act Normally (defect). The table below looks at the payoffs if you don’t lockdown early and already have community transmission.

As Cameron points out: For most people, acting normally is a dominant strategy, at least in the early stages of the coronavirus spreading. They are better off acting normally if everyone else stays home (because they mostly get to go on with their lives as normal, and have low risk of catching the coronavirus; whereas staying home they would be giving up on things they like to do), and they are better off acting normally if everyone else is acting normally (because life goes on as normal, rather than giving up on things they like to do). So, individually people are better off acting normally.

Any voluntary measure is subject to the prisoners’ dilemma which is why we went to an early full lockdown. As we are in lockdown repeated games requires trust and the correct behaviour outlined by the government – this is essential to eliminate the virus. Therefore the dominant strategy of ‘Act Normally’ is no longer an option. Cameron quoted Robert Frank whom I have blogged on here

‘smart for one, dumb for all’.

Stay safe everyone

Internet Penetration vs Use of Cash

The Economist produced some interesting statistics about how the most digitised countries use less cash and the impact of government in moving towards as cashless society. Most transactions are still carried out with cash but the use of it has fallen:

Use of cash – 2013 = 89% and 2019 = 77%

The graph shows the correlation between Internet users and the % of transactions conducted in cash. Nordic countries lead the way and by 2016 it was estimated that 4 out of 5 transactions were done online. In Denmark the extent of the cashless environment has led the payment app called MobilePay to be the top spot as the most “indispensable” app on smartphones – overtaking Facebook, Messenger etc. MobilePay was launched by Danske Bank in 2013 as a peer-to-peer transfer service.

Italy still had 85% of transactions done by cash with 61% internet penetration. Greece with its significant informal economy still has a very high percentage of cash use as it is very hard to trace.

How do countries promote less use of cash?

  • Banks can improve systems that make transfers faster and cheaper
  • Firms promoting the use of credit cards with loyalty schemes
  • Banning the use of cash on public transport – London and Amsterdam
  • Filing tax returns – payments or refunds by Internet banking
  • Making goods cheaper if paying by card

Source: The Economist – August 3rd 2019

A2 Economics – Labour Market – MRPL

Marginal Revenue Product refers to the amount of revenue generated by an additional worker. This is a theory of wages where workers are paid the value of their marginal revenue product to the firm and is based on the assumption of a perfectly competitive labour market. Therefore an employer will hire workers up to the point where the value of the marginal product of labour equals the wage that is being paid. The demand curve for labour can therefore be represented by the value of the marginal product curve – see graph below and a revision mindmap.

Adapted from: AS and A Level Economics Revision by Susan Grant

Mozambique’s monopsony market goes nuts

The primary sector is seen as integral to assisting developing countries grow and raise their standard of living. For the Mozambican economy the cashew industry is an example of this – more than 40% of Mozambican farmers grow and sell cashew, and the processing sector provides formal employment to more than 8,000 individuals. Mozambique is currently the second largest producer in East and Southern Africa and has links with premium export markets, including the United States and Europe.

In the 1960’s the cashew nut industry in Mozambique was in good shape supplying over 50% of global supply and processed most of these domestically and thereby adding employment. However, with a civil war and the instruction from the World Bank in the 1990’s to remove controls and cut taxes on the exports of raw nuts, trading firms shipped out cashews and processed them overseas with significant job losses. But an about turn by the government in 2001 has seen:

  • an export tax of 18-22% for raw nuts
  • a 0% tax for processed kernels.
  • a ban on exports during the first few months of the harvest

16 factories employing 17,000 people, which process about half the cashews sold.

However by having less competition amongst processors – a little like a monopsony market – farmers selling raw cashew nuts are finding that the price of their crop is being reduced by the smaller number of processors. Most cashew nut farmers are smallholders and the government seems to be oblivious to the 1.3m families for the sake of protecting processing jobs.

Monopsony – one buyer many sellers – other examples include:
– large supermarkets, who can dictate terms to smaller suppliers.
– buyers of labour in the labour market.

There is a dilemma for developing countries as when a primary industry starts to expand into the secondary stage of processing, government protection can hurt nut-growers. Just like the coffee industry farmers are at the mercy of a small number of middlemen in this case the processors monopsony power.

Source: Mozambique’s nut factories have made a cracking comeback –
The Economist 12th September 2019

AS Revision – Indirect Tax

The AS multiple-choice paper is coming up and here is this graphic to explain indirect taxes – a popular question. An indirect tax will have the following effects on the market:

Indirect Tax

• The supply curve shifts vertically upwards(effectively a shift to the left) by the amount of the tax(gf) per unit. The price increases but not by the full amount of the tax. This is because of the slopes of the demand and supply curves.
• The consumer surplus is reduced from acp to agb. The portion gbhp of the old consumer surplus is transferred to government in the form of tax.
• The producer surplus is reduced from pce to fde. The portion phdf of the old producer surplus is transferred to the government in the form of tax.
• The market is no longer able to reach equilibrium, and there is a loss of allocative efficiency resulting in the deadweight lost shown by the area bcd. This represents a loss of both consumer surplus bhc and the producer surplus hcd that is removed from the market. The deadweight loss also represents a loss of welfare to an individual or group where that loss is not offset by a welfare gain to some other individual or group.

A2 Revision: Multiple-Choice question on shape of Total Cost curve

Web

With the CIE A2 multiple-choice paper coming, up a popular question concerns the point on the Total Cost curve when MC, AVC, and ATC are at their lowest point. In the graph note the corresponding points on the Total Cost. They usually ask you where on the Total Cost line is the lowest point on the MC curve/AVC curve etc.

Remember:
MC cuts ATC and AVC at their lowest points. The firm will supply where the price is greater than or equal to MC. Thus the individual firm’s supply curve consists of the firm’s MC curve, but only the portion above AVC . The reason for this is that where P=AVC the firm will shut down operations because they are barely covering avoidable costs.

A2 Revision – Long-Run Monopolistic Competition

Monopolistic LR

Here is a quick revision note on monopolistic competition. This is a market structure in which there are a large number of firms selling commodities which are very close substitutes. There are weak barriers to entry and firms may enter the industry with ease. Notice on the diagram that the firm initially makes supernormal profit at Q0 – at MC=MR Price = P0 and Cost = AC0. However with weak barriers to entry these profits are competed away and they now produce at Q1 where at MC=MR and the Price and Cost = AC1

Modern capitalism is characterised by a large number of ‘limited’ monopolies. They are sole suppliers of branded goods, but other firms compete with them by selling similar goods with different brand names. This is the market structure described as monopolistic competition. Thus the commodities produced by any one industry are not homogeneous; the goods are differentiated by branding and the use of trade marks. The individual firm has a monopoly position, but it faces keen competition from firms supplying very similar goods. It has, therefore, only a limited degree of monopoly power – how much depends upon the extent to which firms are free to enter the industry. Product differentiation is emphasised (some would say, created) by the practice of competitive advertising which is, perhaps, the most striking feature of monopolistic competition.

Advertising is employed to heighten in the consumer’s mind the differences between Brand X and Brand Y. It is important to realise that we are concerned with the differentiation of goods in the economic sense and not in the technical sense. Two branded products may be almost identical in their technical features or chemical composition, but if advertising and other selling practices have created different images in the consumer’s mind, then these products are different from our point of view because the consumer will be prepared to pay different prices for them.

A2 Revision – Indifference Curves – Mindmap

With the A2 exam on Wednesday next week here are some notes on indifference curves – it is a good essay to do if you know the theory. The video below is particularly useful.


Income and Substitution Effects with Indifference Curves
Any price change can be conveniently analysed into 2 separate effects – the INCOME EFFECT and the SUBSTITUTION EFFECT.

Income effect of a price change: – when there is a fall in the price of a product, the consumer receives a real income effect and is able to buy more of this and other products in spite of the fact that nominal income is unchanged. If the consumer buys more of the good when the price falls it is a Normal good. If the consumer buys less of the good when the price falls it is seen as an Inferior good.

Substitution effect of a price change: – when there is a rise or fall in the price of a product, the consumer receives a decrease or an increase in the utility derived from each unit of money spent on the product and therefore rearranges demand to maximise utility. This is distinct from the income effect of a price change. For all products, the substitution effect is always positive such that a fall in price leads to an increase in demand as consumers realise an increase in the satisfaction they derive from each unit of money spent on the product.

Remember for normal goods, both the income and substitution effects are positive. But the income effect can be negative: if a negative income effect outweighs the positive substitution effect, this means that less is bought at a lower price and vice-versa. This good is therefore known as a Giffen good.

Giffen goods are generally regarded as goods of low quality which are important elements in the expenditure of those on low incomes. A good example is a basic food such as rice, which forms a significant part of the diet of the poor in many countries. The argument, not accepted by all economists, is that when the price of rice falls sufficiently individuals’ real income will rise to an extent that they will be able to afford more attractive substitutes such as fresh fruit or vegetables to makeup their diet and as a result they will actually purchase less rice even though its price has fallen.

A2 Economics – Contestable Markets

I covered this topic today at the Cambridge A2 Economics revision course. The degree of contestability of a market is measured by the extent to which the gains from market entry for a firm exceed the cost of entering (i.e. the cost of overcoming barriers to entry), with the risks associated with failure taken into account (the cost associated with any barriers to exit). Accordingly, the levels of barriers to entry and exit are crucial in determining the level of a market’s contestability. Barriers to exit consist of sunk costs, that is to say costs that cannot be recovered when leaving the market. The contestable markets approach suggests that potential entrants consider post‑entry profit levels, rather than the pre-entry levels suggested by neo‑classical theory.

Obviously no market is perfectly contestable, i.e. with zero sunk costs. In modern economies it is the degree of contestability which is relevant, some markets are more contestable than others. Also just because there have been no new entrants to a market over a given period of time does not mean that this market is not contestable. The threat of entry will be enough to make the existing (incumbent) firms behave in such a way as to recognise this, i.e. by setting a price which doesn’t attract entry and which only makes normal profits.

Markets which are highly contestable are likely to be vulnerable to ‘hit and run competition’. Consider a situation where existing firms are pricing at above the entry‑limit level. Even in the event that existing firms react in a predatory style, new entry will be profitable as long as there is a time lag between entry and the implementation of such action. Having made a profit in the intervening period, the new entrant can then leave the market at very little cost.

In a contestable market there are no structural barriers to the entry of firms in the long-run. If existing businesses are enjoying high economic profits, there is an incentive for new firms to enter the industry. This increases market competition and dilutes monopoly profits for the incumbent firms. Market contestability requires there are few sunk costs. A sunk cost is committed by a producer when entering an industry but cannot be recovered if a firm decides to leave a market.

Entry limit pricing

The fear on the part of existing firms of rendering the market contestable (stimulating new entry) by making high levels of profit is likely to lead to the adoption of entry limit pricing, a concept introduced in the previous unit. This is essentially a defensive strategy, with existing firms setting prices as high as possible but not so high as to enable new corners to enter the industry. If the existing firms set price at P2 and output at Q2 (see diagram below), it would be possible for a new firm to enter the industry and supply Q1. Total market supply would then be Q3 (Q1 + Q2), the price would be P3 and the new firm would be covering its costs. If, instead, the existing firms chose to produce at Q3 (with price level P3), the new firm producing Q1 (total market supply would now be Q4 at price P4) would not be covering its costs and would have to exit the industry in the long run.

The video below on the Airline Industry in the US from Commanding Heights series is a good example of breaking down monopoly power.

Source:

Anforme – A2 Level Economics Revision Booklet.

A2 Economics – Dominant Firm Model

Price leadership (dominant firm model) was part of a question in last week’s A2 Economics exam and was not well answered. This example of collusive pricing sees one firm act as the leader in the market, setting the price which the other firms then adopt. The price leader is usually the ‘dominant firm’ in the market, this position being achieved through some factor such as size or cost advantage. The graph illustrates the dominant firm model. The dominant firm sets the price where MC = MR (profit maximisation) and then allows the other firms to supply as much as they wish at this price 0-Q1. The dominant firm supplies the remaining, or residual, market demand Q1-Q2. This behaviour offers all firms the advantage of certainty; the dominant firm is able to set the price, while the remaining firms know that they will be able to supply as much as they wish at the price set.