Forms of efficiency
　　In order to decide whether a capital market exhibits pricing efficiency， research must be undertaken into security price movements and whether it is possible to make abnormal gains by acting on different kinds of information. Most of this research has been based on ordinary share price movements and three forms of efficiency can be described.
　　Weak form efficiency refers to a market where share prices fully and fairly reflect all past information. In such a market， it is not possible to make abnormal gains by studying past share price movements. Research has shown that capital markets are weak form efficient and that share prices appear to follow a ‘random walk’， the random changes in share prices resulting from the unpredictable arrival of favourable and unfavourable information on the market.
　　Semi-strong form efficiency refers to a market where share prices fully and fairly reflect all publicly available information in addition to all past information. In such a market it is not possible to make abnormal gains by studying publicly available information such as the financial press， company financial statements and records of past share price movements. Research has shown that well-developed capital markets such as the London Stock Exchange and the New York Stock Exchange are semi-strong form efficient.
　　Strong form efficiency refers to a market where share prices fully and fairly reflect not only all publicly available information and all past information， but also all private information (insider information) as well. In such a market， it is not possible to make abnormal gains by studying any kind of information. Since it is always possible to make abnormal gains by using insider information (even if governments have made this illegal)， even well-developed capital markets cannot be described as strong form efficient. However， investors and analysts are often accurate in their estimates of what is happening inside companies and financial management theory considers well-developed capital markets to be highly efficient.
　　Product markets and the problem of monopoly
　　Another market matter in Section 2 of the Paper 2.4 syllabus is regulation of business. One example suggested is pricing restrictions. This can be illustrated by looking at the problem of monopoly in product markets and how to respond to it.
　　One possible result of a company being successful in its chosen market is that it gains increasing market share. This may be due to its competitors going out of business or as a result of taking over its competitors. If the trend continues， a successful company may end up with no real competition at all. It is then in a position to earn monopoly profits by selling at prices higher than would be found in a more competitive market.
　　The positive consequences of monopoly
　　There may be a circumstance in which a monopoly may be desirable， for example when size is necessary for efficient production of a particular product， i.e. through economies of scale2. This has been claimed to be true of utilities such as water distribution and electricity production.
　　It is worth noting in this respect that successive UK governments have felt the need to artificially maintain competition in the markets served by privatised UK utilities， implying that utilities naturally tend towards a monopoly. It has also been suggested that monopoly may be the natural reward for entrepreneurial activity by businesses， or the logical consequence of a focus on shareholder wealth maximisation.
　　The negative consequences of monopoly
　　The negative consequences of monopoly are usually felt to outweigh any positive outcomes. Society and the public can suffer as a result of monopoly. Not only do consumers pay higher prices in order to support monopoly profits， but they may be offered a reduced product range. Society can also suffer through the inefficient use of economic resources in the production process， a decrease in innovation and product development， and a lack of incentives for a monopoly to reduce managerial and other inefficiencies.
　　Government regulation of monopoly
　　Consumers cannot deal with monopolies and so this regulatory role is usually assumed by governments. Many governments， including those of the UK， EU and USA， have long histories of regulatory intervention in product and consumer markets. Their aims can be to stop monopolies arising， to prevent abuse of a dominant position in a particular market， to prevent the creation of price-fixing cartels， and to preserve and maintain competition.
　　In the UK， these objectives are achieved through the actions of the Office of Fair Trading and the UK Competition Commission， which are required to monitor， investigate and make binding recommendations in situations where a potential monopoly may arise. The criteria used to initiate an investigation can be quite broad： UK legislation， for example， considers that a monopoly position may arise when a company has a market share of 25 per cent or more， of a particular market3.
　　Product markets and the problem of externalities
　　Excessive profits can be gained by companies which do not pay the full economic cost for their production processes. For example， a company which causes environmental pollution does not bear the full cost of its inefficient production process， but transfers the cost of cleaning up its waste products as an externality to society as a whole. Externalities are social costs or benefits arising from economic decisions of individual economic agents such as companies4.
　　Governments may need to intervene in product markets to require companies to bear more of the cost of the externalities they produce. In other words， they may adopt green policies， another example of regulation of business suggested in Section 2 of the Paper 2.4 syllabus.
　　Green policies can result in increased production costs as companies are required by legislation to reduce the environmental impact of their business operations. These increased costs will reduce company profits unless they are passed on to customers through increased prices. If price increases occur， green policies can result in the reduction of externalities and the transfer of their costs from society to consumer.
　　Green policies can therefore be seen as leading to fairer prices in particular product markets since these prices reflect more completely the economic resources consumed in the production of the products offered for sale.
　　Money and capital markets and the cost of money
　　Section 2 of the Paper 2.4 syllabus also refers to rates of interest and yield curves. Both interest rate and yield can be seen as the cost of money， i.e. the price of money set by the interaction of the supply of funds and the demand for funds in a particular market.
　　It is important to recognise that interest rate and yield have different meanings. Interest rate is the percentage return on the nominal (or money) amount of debt issued. Yield can either mean interest rate divided by market price (often referred to as running yield)， or it can mean the discount rate that makes the present value of future interest payments and redemption value equal to the current market price (referred to as the redemption yield or the cost of debt).
　　Consider a bond with a market value of ?102.53 that pays 10 per cent per year for three years before being redeemed at par. Its interest rate (or coupon) is 10 per cent. Its running yield is 100 x (10/102.53)= 9.75 per cent. Its redemption yield or cost of debt (found by linear interpolation) is 9 per cent.
　　The longer the period over which debt is offered， the greater is the risk to the lender that the borrower may be unable to meet interest payments， or be unable to repay the principal amount borrowed. This means that as the time to redemption or repayment increases， the risk of default also increases， and we expect that lenders would require a higher return to compensate for this increased risk. If we consider default risk alone， we would expect long-term debt to be more expensive than short-term debt.
　　There are other factors to consider in discussing the relative risk and cost of long-term and short-term debt. The important point to grasp， however， is that long-term debt is usually expected to be more expensive than short-term debt (i.e. the yield curve slopes upwards)， unless other factors arise which act to change the normal state of affairs. Expectations theory， market segmentation theory and liquidity preference theory consider the different costs of debt of differing maturities， and students should consider these as possible explanations of yield curves which do not slope smoothly upwards5.
　　It is essential that candidates carefully study the content of Section 2 of the Paper 2.4 syllabus， since an understanding of this section is essential if the objectives of the syllabus as a whole are to be achieved.
　　References
　　1. Watson， D and Head， A (2001) Corporate Finance： Principles and Practice (Financial Times Prentice Hall)， p29
　　2. Griffiths， A and Wall， S (2001) Applied Economics (Financial Times Prentice Hall)， pp103-6
　　3. Griffiths， A and Wall， S (2001) Applied Economics (Financial Times Prentice Hall)， p108
　　4. Griffiths， A and Wall， S (2001) Applied Economics (Financial Times Prentice Hall)， p178
　　5. Arnold， G (2002) Corporate Financial Management (Financial Times Prentice Hall)， pp495-9