Renewables are now the cheapest form of energy generation. If all energy use in the UK was based on electricity, and all electricity was generated by renewables, our current cost of living crisis would be far less severe, and of course we would not be adding to climate change. Furthermore, there is huge potential in the UK (and most other countries) for far more renewable energy production than we currently have. So why isn’t this happening faster?
That is the question addressed in a new book by Eric Lonergan and Corinne Sawers. In many ways it is a very optimistic book, because it suggests the problem of climate change is mainly solvable with known technology, and there are no insurmountable barriers for doing this with sufficient speed to enable us to avoid severe global warming. They suggest that the reason this is not happening is, in part, because we are thinking about it in the wrong way.
Much of the discussion around avoiding climate change is framed in terms of costs. Economists are partly to blame for this, as the debate was originally framed by economists in terms of what current costs are we prepared to pay to avoid future costs (global warming). The book suggests that a better way of thinking about it is as an industrial revolution, such as the invention of telecommunications. Because renewable energy is cheaper, we are better off developing it and phasing out fossil fuels even without the problem of future global warming. When electricity was first invented, no one talked about the costs of installing electricity generation compared to future benefits, because it was obviously a better technology for everyone concerned.
An economist might retort that there is always an opportunity cost of investing in green energy and electrification, because that investment could be used for something else. In this sense it is always right to talk about costs and benefits. However in today’s world we have very low long term interest rates, and yet in many countries private and/or public investment levels are if anything lower than the past. The trade-off in many cases may not be between green investment and some other form of investment, but between green investment and the spending power of those who own shares in companies.
Another strand of thinking suggests radical change, like individually consuming less or eating different foods, or for economies to stop growing, or fundamentally changing capitalism. Again this makes stopping climate change seem rather unattractive or risky, and this puts both people and policymakers off. Framing the problem as a green industrial revolution to obtain cheaper and more stable energy is much more appealing.
In terms of doing this faster, the book suggests looking at what has worked so far, that has brought us to the point where renewable energy is also the cheapest energy: a combination of large positive incentives and hard regulations. Central to their argument are the use of “extreme positive incentives for change”. These have led to the rapid reduction in the cost of solar power, and the widespread adoption of electric vehicles in parts of China, Scandinavia and the US.
Extreme positive incentives (like providing large subsidies for electric cars or well insulated houses for example) combine three important pieces of psychology, politics and economics that are often ignored by economists. The first is that extreme incentives are much more effective than marginal incentives, because of the psychological fixed costs of changing behaviour. The second is that positive incentives (giving people money to do things) are more effective than negative incentives (like taxing carbon), because the latter generates resistance and as a result are unlikely to be pursued strongly by policymakers.
The third is that people do not ‘internalise the government’s budget constraint’, which is the idea behind Ricardian Equivalence. If they did. people would recognise that incentives had to be paid for by them one way or another, so positive incentives and taxes would work in the same way. This doesn’t happen not because people are irrational, but because it is very uncertain how governments fund incentives, and many of those methods of funding would not fall on those receiving the incentive. So people who receive an incentive really are better off, and those who are taxed are worse off, in terms of expected income. It is only the fiction of the representative agent (and various additional assumptions) that leads to the idea of internalising the government’s budget constraint. 
We can see all this in action when we compare the success of solar power to the many difficulties governments have had in raising appropriate carbon taxes (or permits that act like taxes). Carbon taxes make sense in many ways, because they are the economists’ standard response to an externality (i.e. a cost imposed on others that isn’t paid for by the people generating that cost). Climate change is the biggest externality of our lifetime. Yet in the case of climate change, when the costs are generated by everyone and the harm they create is in the future, the psychological, political and economic factors noted above mean positive extreme incentives are much more effective than carbon taxes.
All of which brings me to the title of this post. If extreme positive incentives are what is needed to speed up electrification and the use of renewables to generate that electricity, that will cost governments money. Ideally that should be paid for by higher general taxes rather than borrowing, because it’s better if the polluter pays. (Equally richer countries, that have already deposited a large amount of carbon in the atmosphere, should help pay poorer countries to go green.) But this ideal may not be feasible in political terms, because policymakers will resist the idea of tax increases and therefore will not provide the incentives.
The way to avoid this problem is to fund green incentives through borrowing. As I have often said, future generations suffering the effects of substantial global warming will not think that’s OK because we reduced their ‘burden’ of paying taxes on government debt. Instead they will positively welcome the borrowing required to reduce climate change in the past.  This is particularly so when that borrowing currently costs so little.
Which is where debt and deficit targets get in the way. To see how ridiculous it would be if they did get in the way, just compare why we need debt and deficit targets, and compare that to why we need to mitigate climate change. Deficit targets are useful to prevent irresponsible governments from buying elections or rewarding donors by tax or spending breaks funded by borrowing. We need to reduce global warming because otherwise we will see, for example, large-scale global starvation and migration, with all the political chaos that this will cause. If you had to choose between reducing the fiscal behaviour of irresponsible governments and reducing climate change, which would you choose?
There may be ways of not choosing between the two. Perhaps we could create two separate sets of government accounts: a normal account and a green account. Deficit targets could apply to the former but not the latter. If Germany can do this for military spending following Putin’s invasion of Ukraine, why not do it for spending required to reduce climate change?  Of course there will be many practical political problems, and it may require a fiscal council with teeth to avoid governments cheating, but it’s clear we should be at least discussing this possibility.
If we don’t do something like this, then we may be faced with a simple choice. Do we speed up greening the economy to reduce the extent of global warming using the ideas proposed by Lonergan and Sawers, or do we do what this government and the media are doing now, and obsess about deficit and debt targets? The fate of the planet may depend on what people and governments choose.
 In a simple model with a representative agent, a subsidy would automatically imply an equal tax today or tomorrow, which will leave the representative agent no better off, so they would be indifferent between positive incentives (subsidies) and negative incentives (like carbon taxes). In reality the tax increases required by any subsidies may fall on different people from those receiving a specific tax cut or incentive. In addition tax cuts today may be paid for by cuts in government spending, which again may not fall on those receiving a specific incentive, and so on. In other words people see positive incentives for them as redistribution to them, and taxes on them as redistribution from them.
 The classic case for funding by borrowing is an investment that doesn’t just benefit people today, but also benefits people tomorrow. This is why no macro restrictions should be put on public investment. However many activities that are not classed as public investment have these characteristics. A war, for example, is often an investment in the future, which is why wars are so often accompanied by public borrowing. Greening the economy also has those characteristics.
 Does it make sense to treat higher military expenditure as different from other forms of spending? If it represents a one-off increase in spending, reflecting for example an unusually aggressive ruler in a nearby country then yes, it is. However if it is seen as a permanent increase in spending, it is not clear why that shouldn’t be paid for by the current generation through higher taxes.