Tag: social optimum

Politicians, business leaders, climate scientists, interest groups and journalists from across the world have been meeting in Dubai at the COP28 climate summit (the 28th annual meeting of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC)). The meeting comes at a time when various climate tipping points are being reached or approached – some bad, but some good. Understanding these tipping points and their implications for society and policy requires understanding not only the science, but also the various economic incentives affecting individuals, businesses, politicians and societies.

Tipping points

A recent report (see first reference in articles section below) identified various climate tipping points. These are when global temperatures rise to a point where various domino effects occur. These are adverse changes to the environment that gather pace and have major effects on ecosystems and the ability to grow food and support populations. These, in turn, will have large effects on economies, migration and political stability.

According to the report, five tipping points are imminent with the current degree of global warming (1.2oC). These are:

  • Melting of the Greenland ice sheet;
  • Melting of the West Antarctic ice sheet;
  • Death of warm-water coral reefs;
  • Collapse of the North Atlantic Subpolar Gyre circulation, which helps to drive the warm current that benefits Western Europe;
  • Widespread rapid thawing of permafrost, where tundra without snow cover rapidly absorbs heat and releases methane (a much more powerful source of global warming than CO2).

With global warming of 1.5oC, three more tipping points are likely: the destruction of seagrass meadows, mangrove swamps and the southern part of the boreal forests that cover much of northern Eurasia. As the temperature warms further, other tipping points can interact in ways that drive one another, resulting in tipping ‘cascades’.

But the report also strikes an optimistic note, arguing that positive tipping points are also possible, which will help to slow global warming in the near future and possibly reverse it further in the future.

The most obvious one is in renewable energy. Renewable power generation in many countries is now cheaper than generation from fossil fuels. Indeed, in 2022, over 80% of new electricity generation was from solar and wind. And as it becomes cheaper, so this will drive investment in new renewable plants, including in small-scale production suitable for use in developing countries in parts not connected to a grid. In the vehicle sector, improved battery technology, the growth in charging infrastructure and cheaper renewable sources of electricity are creating a tipping point in EV take-up.

Positive tipping points can take place as a result of changing attitudes, such as moving away from a meat-intensive diet, avoiding food waste, greater use of recycling and a growth in second-hand markets.

But these positive tipping points are so far not strong enough or quick enough. Part of the problem is with economic incentives in market systems and part is with political systems.

Market failures

Economic decisions around the world of both individuals and firms are made largely within a market environment. But the market fails to take into account the full climate costs and benefits of such decisions. There are various reasons why.

Externalities. Both the production and consumption of many goods, especially energy and transport, but also much of agriculture and manufacturing, involve the production of CO2. But the costs of the resulting global warming are not born directly by the producer or consumer. Instead they are external costs born by society worldwide – with some countries and individuals bearing a higher cost than others. The result is an overproduction or consumption of such goods from the point of view of the world.

The environment as a common resource. The air, the seas and many other parts of the environment are not privately owned. They are a global ‘commons’. As such, it is extremely difficult to exclude non-payers from consuming the benefits they provide. Because of this property of ‘non-excludability’, it is often possible to consume the benefits of the environment at a zero price. If the price of any good or service to the user is zero, there is no incentive to economise on its use. In the case of the atmosphere as a ‘dump’ for greenhouse gases, this results in its overuse. Many parts of the environment, however, including the atmosphere, are scarce: there is rivalry in their use. As people increase their use of the atmosphere as a dump for carbon, so the resulting global warming adversely affects the lives of others. This is an example of the tragedy of the commons – where a free resource (such as common land) is overused.

Inter-generational problems. The effect of the growth in carbon emissions is long term, whereas the benefits are immediate. Thus consumers and firms are frequently prepared to continue with various practices, such as driving, flying and using fossil fuels for production, and leave future generations to worry about their environmental consequences. The problem, then, is a reflection of the importance that people attach to the present relative to the future.

Ignorance. People may be contributing to global warming without realising it. They may be unaware of which of the goods they buy involve the release of carbon in their production or how much carbon they release when consumed.

Political failures

Governments, whether democratic or dictatorships, face incentives not to reduce carbon emissions – or to minimise their reduction, especially if they are oil producing countries. Reducing carbon involves short-term costs to consumers and this can make them unpopular. It could cost them the next election or, in the case of dictatorships, make them vulnerable to overthrow. What is more, the oil, coal and gas industries have a vested interest in continuing the use of fossil fuels. Such industries wield considerable political power.

Even if governments want the world to reduce carbon emissions, they would rather that the cost of doing so is born less by their own country and more by other countries. This creates a prisoner’s dilemma, where the optimum may be for a large global reduction in carbon emissions, but the optimum is not achieved because countries individually are only prepared to reduce a little, expecting other countries to reduce more. Getting a deal that is deemed ‘fair’ by all countries is very difficult. An example is where developing countries, may feel that it is fair that the bulk of any cuts, if not all of them, should be made by developed countries, while developed countries feel that fixed percentage cuts should be made by all countries.

Policy options

If the goal is to tackle climate change, then the means is to reduce the amount of carbon in the atmosphere (or at the least to stop its increase – the net zero target). There are two possibilities here. The first is to reduce the amount of carbon emissions. The second is to use carbon capture and storage or carbon sequestration (e.g. through increased forestation).

In terms of reducing carbon emissions, the key is reducing the consumption of carbon-producing activities and products that involve emissions in their production. This can be achieved through taxes on such products and/or subsidies on green alternatives (see the blog ‘Are carbon taxes a solution to the climate emergency?‘). Alternatively carbon-intensive consumption can be banned or phased out by law. For example, the purchase of new petrol or diesel cars cold be banned beyond a certain date. Or some combination of taxation and regulation can be used, such as in a cap-and-trade system – for example, the EU Emissions Trading System (EU ETS) (see the blog ‘Carbon pricing in the UK‘). Then there is government investment in zero carbon technologies and infrastructure (e.g. electrifying railways). In practice, a range of policy instruments are needed (see the blog ‘Tackling climate change: “Everything, everywhere, all at once”‘).

With carbon capture, again, solutions can involve a mixture of market mechanisms and regulation. Market mechanisms include subsidies for using carbon capture systems or for afforestation. Regulation includes policies such as requiring filters to be installed on chimneys or banning the felling of forests for grazing land.

The main issue with such policies is persuading governments to adopt them. As we saw above, governments may be unwilling to bear the short-term costs to consumers and the resulting loss in popularity. Winning the next election or simple political survival may be their number-one priority.


The COP28 summit concluded with a draft agreement which called for the:

transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050 in keeping with the science.

This was the first COP summit that called on all nations to transition away from fossil fuels for energy generation. It was thus hailed as the biggest step forward on tackling climate change since the 2015 Paris agreement. However, there was no explicit commitment to phase out or even ‘phase down’ fossil fuels. Many scientists, climate interest groups and even governments had called for such a commitment. What is more, there was no agreement to transition away from fossil fuels for transport, agriculture or the production of plastics.

If the agreement is to be anything more than words, the commitment must now be translated into specific policy actions by governments. This is where the real test will come. It’s easy to make commitments; it’s much harder to put them into practice with policy measures that are bound to impose costs on various groups of people. What is more, there are powerful lobbies, such as the oil, coal and steel industries, which want to slow any transition away from fossil fuels – and many governments of oil producing countries which gain substantial revenues from oil production.

One test will come in two years’ time at the COP30 summit in the Amazonian city of Belém, Brazil. At that summit, countries must present new nationally determined commitments that are economy-wide, cover all greenhouse gases and are fully aligned with the 1.5°C temperature limit. This will require specific targets to be announced and the measures required to achieve them. Also, it is hoped that by then there will be an agreement to phase out fossil fuels and not just to ‘transition away’ from them.

Reasons for hope

Despite the unwillingness of many countries, especially the oil and coal producing countries, to phase out fossil fuels, there are reasons for hope that global warming may be halted and eventually even reversed. Damage will have been done and some tipping points may have been reached, but further tipping points may be averted.

The first reason is technological advance. Research, development and investment in zero carbon technologies is advancing rapidly. As we have seen, power generation from wind and solar is now cheaper than from fossil fuels. And this cost difference is likely to grow as technology advances further. This positive tipping point is becoming more rapid. Other technological advances in transport and industry will further the shift towards renewables and other advances will economise on the use of power.

The second is changing attitudes. With the environment being increasingly included in educational syllabuses around the world and with greater stress on the problems of climate change in the media, with frequent items in the news and with programmes such as the three series of Planet Earth, people are becoming more aware of the implications of climate change and how their actions contribute towards the problem. People are likely to put increasing pressure on businesses and governments to take action. Growing awareness of the environmental impact of their actions is also affecting people’s choices. The negative externalities are thus being reduced and may even become positive ones.



  1. Use a diagram to demonstrate the effects of negative externalities in production on the level of output and how this differs from the optimum level.
  2. Use another diagram to demonstrate the effects of negative externalities in consumption on the level of consumption and how this differs from the optimum level.
  3. What was agreed at COP28?
  4. What incentives were included in the agreement to ensure countries stick to the agreement? Were they likely to be sufficient?
  5. What can governments do to encourage positive environmental tipping points?
  6. How may carbon taxes be used to tackle global warming? Are they an efficient policy instrument?
  7. What can be done to change people’s attitudes towards their own carbon emissions?

It’s a relatively common dish to see on a menu at a restaurant: mackerel. This particular fish has been promoted as a healthy and sustainable dish, but now its sustainability is coming into question and the Marine Conservation Society has taken it off its ‘fish to eat’ list. My brother Hugh is a marine biologist and often comments on which fish we should be avoiding due to sustainability issues (especially given how much I like fish!) So, how is this an economics issue?

There a couple of key things to pick out here. Firstly, with the conservationists’ warning of this issue of unsustainability, they have been asking consumers to reduce the amount of mackerel they buy. This will naturally have an impact on fisherman. If consumers do listen to the conservationists and hence reduce their demand for mackerel, we could see a fall in the price of this fish and a reduction in the fishermen’s turnover. It could be that we see a switch in consumption to other more sustainable fish, especially if we see some form of intervention.

Another area concerning economics is the idea of over-fishing. For years, there have been disputes over who has the rights to these fish stocks. In the past, the Faroe Isles and Iceland have increased their quotas significantly, as mackerel appear to have migrated to their shores, contributing to this question of sustainability. Iceland and the Faroe Isles have ‘unilaterally agreed their quotas … as they are not governed by the common fisheries policy’.

The question is: when fisherman catch one additional mackerel, what are they considering? Do they think about the private benefit to them (or their company) or do they consider the external cost imposed on others? Whenever one fish is taken from the sea, there is one less fish available for other fishermen.

This leads to over-consumption of fish and contributes towards the well-documented depletion of fish stocks and ‘The Tragedy of the Commons’, if account is not taken of the external cost imposed on other fishermen.

The total catch is now far in excess of what has been scientifically recommended and previously agreed upon by all participating countries. Negotiations to introduce new catch allowances have so far failed to reach agreement.

There are hopes that an international policy on quotas can be agreed to ensure mackerel levels return to or remain at a sustainable level. However, at present no progress has been made. Until some form of an agreement is reached, fishermen around Iceland and the Faroe Isles will continue to battle against the conservationists. The following articles consider this fishy topic.

Mackerel taken off conservationists’ ‘fish-to-eat’ list The Guardian, Rebecca Smithers (22/1/13)
Warning over mackerel stocks Scottish Herald (22/1/13)
Fishing quota talks begin amid ongoing disputes and finger-pointing The Scotsman, Fran Urquhart (14/1/13)
Mackerel no longer an ethical choice because of over-fishing The Telegraph, Louise Gray (22/1/13)
Ths fishy tale of macro-mismanagement The Guardian, Annalisa Barbieri (22/1/13)
You can still eat mackerel – just make sure it’s British The Telegraph, Louise Gray (22/1/13)
Dispute means mackerel is no longer fish of the day BBC News, Matt McGrath (22/1/13)
Mackerel struck off sustainable fish list Associated Press (22/1/13)


  1. Why are quotas set by the EU for fishing? Who do they apply to?
  2. Why is there an externality from fishing?
  3. What is the Tragedy of the Commons? Using a diagram with average and marginal revenue product and average and marginal cost illustrate the market equilibrium and the social optimum. Why are they different?
  4. Following on from question 3, what does this suggest about the role of governments?
  5. If the conservationists’ request regarding buying less mackerel is successful, what impact might this have on fishermen and fisheries?
  6. If consumers do switch to buying other fish, what would happen to the equilibrium in the mackerel market and in the market for other fish? Think about this question in terms of general equilibrium analysis.

A campaign to introduce a tax on disposable plastic bags in England has been launched by various pressure groups, including The Campaign to Protect Rural England (CPRE), Keep Britain Tidy, the Marine Conservation Society and Surfers Against Sewage. Plastic bags, they maintain, litter streets and the countryside and pollute the seas, where they cause considerable damage to marine life.

They propose a tax of 5p per bag, which would be passed on to consumers. Such a levy has already been introduced in Wales in October 2011. As a result, plastic bag use in Wales has dropped dramatically (see also the full report from the Welsh Government). The Scottish Government and the Northern Ireland Assembly are also planning introducing similar charges.

Many other governments have introduced taxes, charges or bans on plastic bags and many more are considering introducing such measures. Ireland introduced a 15 euro cent charge on single-use plastic bags as far back as 2002 and saw a 94% reduction in plastic bag use (328 per person per year to 21). The charge was raised to 22 euro cents in 2007 after bag use rose to 30 per person.

Other countries have banned plastic bags altogether: some, such as Rwanda and Somalia have banned all plastic bags; others, such as China and South Africa have banned very thin bags; others, such as Italy, have banned non-biodegradable ones.

In the USA, various states or districts have introduced levies and in the EU, where more than four billion bags are thrown away each year, the European Commission will soon publish proposals for limiting the use of plastic bags.

So what are the arguments for limiting the use of plastic bags? Why is it not enough to leave things simply to the market? And if the use of plastic bags is to be reduced, what’s the most efficient way of doing so? Are there any problems with alternatives to plastic bags? The following articles and reports consider these questions?

England urged to pick up Wales’ plastic bag levy businessGreen, Jessica Shankleman (1/8/12)
Wales’ plastic bag charge yields massive green savings businessGreen, Jessica Shankleman (5/7/12)
Supermarkets ‘should charge £1 a bag’ BBC Today Programme, Samantha Harding and Judith Holder (2/8/12)
Environmentalists team up to push for bag tax in England Plastics News, Anthony Clark (1/8/12)
Break the Bag Habit Keep Britain Tidy (1/8/12)
Plastic bag use ‘up for second year running’ Guardian, Rebecca Smithers (5/7/12)
Plastic bag use in Wales plummets due to 5p charge, figures show Guardian, Adam Vaughan (4/7/12)
Carrier bag charge ‘effective and popular’ figures reveal ITV News (4/7/12)
What should be done about plastic bags? BBC News Magazine, Chris Summers (19/3/12)
Irish bag tax hailed success BBC News, Chris Summers (20/8/02)
The Big Fix The Math Behind Sacking Disposable Bags Atlantic Cities, Nate Berg (26/9/11)
Fremantle moves to ban plastic bags ABC News, Lucy Martin (23/7/12)
Bans Plastic Bag Ban Report, Ted Duboise (updated)
Vote With Your Dollars, and Also Vote New York Times, Gernot Wagner (30/7/12)

Evaluation Of The Introduction Of The Single-Use Carrier Bag Charge In Wales: Attitude Change And Behavioural Spillover, Wouter Poortinga, Lorraine Whitmarsh and Christine Suffolk Report to Welsh Government by Cardiff University (June 2012)
Life cycle assessment of supermarket carrierbags: a review of the bags available in 2006 Environment Agency, Joanna Marchant (25/7/11)
Stakeholder consultation on options to reduce the use of plastic carrier bags … EC Environment (19/3/12)


  1. Draw a diagram demonstrating the externalities involved in the use of plastic bags. Show the marginal private and social costs and benefits and the socially efficient level of consumption.
  2. How would you set about establishing the amount of consumer surplus from the use of plastic bags at a zero price?
  3. Compare the relative social efficiency of a tax on plastic bags with a ban on plastic bags.
  4. Would education be an effective alternative to taxing plastic bags?
  5. Why might it be difficult to get supermarkets and other retailers to agree to a voluntary ban on giving out free plastic bags?
  6. Why might it be extremely difficult in practice to establish the socially efficient price for plastic bags?

No market is perfect and when the market mechanism fails to deliver an efficient allocation of resources, we say the market fails and hence there is justification for some government intervention. From a monopolist dominating an industry to a manufacturing firm pumping out pollution, there are countless examples of market failure.

The Guardian is creating a guide to climate change, covering areas from politics to economics. The problem of climate change has been well documented and this blog considers a particular issue – the case for climate change or the environment as a market failure. In many cases just one market failure can be identified, for example an externality or a missing market. However, one of the key problems with climate change is that there are several market failures: externalities in the form of pollution from greenhouse gases; poor information; minimal incentives; the problem of the environment as a common resource and the immobility of factors of production, to name a few. Each contributes towards a misallocation of resources and prevents the welfare of society from being maximised.

When a market fails, intervention is justified and economists argue for a variety of policies to tackle the above failures. In a first-best world, there is only one market failure to tackle, but in the case of the environment, policy must be designed carefully to take into account the fact that there are numerous failings of the free market. Second-best solutions are needed. Furthermore, as the problem of climate change will be felt by everyone, whether in a developed or a developing country, international attention is needed. The two articles below are part of the Guardian’s ultimate climate change guide and consider a huge range of economic issues relating to the problem of environmental market failure.

Why do economists describe climate change as a ‘market failure’? Guardian, Grantham Research Institute and Dunca Clark (21/5/12)
What is the economic cost of climate change? Guardian (16/2/11)


  1. What is meant by market failure?
  2. What are the market failures associated with the environment and climate change? In each case, explain how the issue causes an inefficient allocation of resources and thus causes the market to fail? You may find diagrams useful!
  3. What is meant by the first-best and second-best world?
  4. What does a second-best solution aim to do?
  5. Using diagrams to help your explanation, show how a tax on pollution will have an effect in a first best world, where the only market failure is a negative externality and in a second best world, where the firm in question is also a monopolist.
  6. What solutions are there to the problem of climate change? How effective are they likely to be?
  7. Does the need to tackle climate change require international co-operation? Can you use game theory to help your explanation?!

The following video and audio podcasts look at resistance by the US oil and coal industries to measures to curb the consumption of oil and coal. Despite the clearly estabilised link between burning fossil fuels and global warming, many in the two industries reject, or at least question, the evidence. After all, it is in their commerical interests to promote the consumption of fossil fuels!

Elsewhere in the USA, interesting scientific developments are taking place to combat global warming. One measure is the production of ‘green oil’ produced from algae. Growing the algae absorbs carbon from the atmosphere.

In few areas are economic arguments so intertwined with political ones. The podcasts look at some of the issues.

Energy policy divides in the US BBC News, David Shukman (2/11/09)
America’s energy policy dilemma BBC News, David Shukman (2/11/09)
Texas takes on green energy BBC News, Roger Harrabin (1/06/09)
Ethical Man: Green revolution in Texas BBC Newsnight, Justin Rowlatt (11/3/09)
Climate plans part of wider battle over American freedom Ethical Man (Justin Rowlatt) blog (BBC) (3/11/09)
Obama urges climate change effort BBC News (3/11/09)
Al Gore on tackling global warming BBC Newsnight (4/11/09)
Al Gore on beating the ‘oil habit’ BBC Today Programme (4/11/09)


  1. To what extent will the free market result in a shift to greener energy sources? Why will any shifts towards greener fuels still not result in the socially or environmentally optimum use of fossil and ‘green’ fuels without government intervention?
  2. What policies could governments adopt to internatlise the externalities involved in burning fossil fuels?
  3. How suitable are cap-and-trade policies (tradable permits) for tackling global warming? What conditions are necessary for such policies to be effective?
  4. Why is tackling climate change politically difficult for (a) individual countries and (b) the world as a whole? How is game theory relevant to your analysis?