It is hard to overstate the significance of President Donald Trump’s Liberation Day US tariff plan, announced last week. It is a rewriting of the world order – and America’s place in it. It’s going to take more than one article from me to explore its significance. This time I want to look at the general context – as this is essential to understanding how things might develop from here – and it is very widely misunderstood by even expert commentators. The president’s action looks like one of the most colossal acts of self-harm in history – but the impact on the rest of the world may not be as bad as many suggest.
Any discussion of the economics of trade must start with the idea of comparative advantage – first articulated by David Riccardo 200 years ago. It is one of the most powerful economic ideas out there, and it is also one of the most neglected. I don’t want to go back to Economics 101 here. Suffice to say that the theory shows that trade is driven by opportunity costs and not productivity. There is a limit to how much each country can produce – and if each one specialises where it is relatively the most efficient (but not necessarily in absolute terms) then production across the world is maximised and everybody should benefit. Differences in actual productivity are taken care of by exchange rate differentials. It is why equilibrium exchange rates do not conform to purchasing power parity. “Comparative Advantage” may sound rather like “Competitive Advantage”, and we may often make an analogy between a country and a firm (“UK plc”) – but they are very different things. In economics firms compete but countries do not – they optimise. Tariffs, meanwhile, distort pricing signals and lead countries to sub-optimise.
This theory does a wonderful job of explaining the world we see today – why there is so much trade, and why and how exchange rates differ from purchasing power parity (i.e. currencies buy different amounts of goods and services in different countries). What it doesn’t do is help with the sort of fine-grained predictions needed for economic models. That requires a very detailed understanding of economies and what the opportunity costs are – way beyond the capabilities of current economic data and analysis. Attempts to model it at an intermediate level, by looking at broad factors of production (land, human capital, etc.), have failed. In modern economics, if you can’t put it into a model, it’s no use at all. So while most economists have a general idea about comparative advantage, it’s a distant memory from their undergraduate days. They haven’t thought about it very much. Politicians and political commentators pick up on the general idea but garble it – falling into a fallacy of composition (assuming that the production side of an economy is analogous to a firm) and muddling competitive and comparative advantage.
Two insights get lost in all this. The first is that the theory has nothing to say about trade deficits and surpluses. In the standard exposition, exchange rates should adjust so there are no deficits or surpluses – though whether this applies country to country, or to countries across all their trading relationships is an interesting question that I’m unable to answer. I will come back to that. The second is that the benefits of trade are driven by difference – and that the more similar economies become the fewer gains from trade there will be. Let’s take a closer look at that in the context of the US and China.
In 1990, when trade between the two countries started to open up, the US was one of the world’s most advanced economies and China one of the least developed, after the failure of Maoist Communism. Most of China’s workforce was tied up in massively unproductive agriculture. Only a tiny proportion of America’s was in its hyperproductive productive agriculture. America had a massive comparative advantage in agriculture; China therefore had a comparative advantage in pretty much everything else that was tradable, apart from technologically advanced goods that were beyond its capability. To put this another way, China’s hideously unproductive agriculture sector meant that Chinese wages were tiny compared to America’s, which meant that even very inefficient manufacturing businesses were highly competitive. And so they had the basis of massively beneficial gains from trade. America exported agricultural products and advanced goods, while importing cheap manufactured goods. Both countries benefited from cheaper inputs.
So far, so good. But the situation was dynamic. Rural workers in China responded to the demand for extra manufacturing jobs; rural productivity improved. Chinese manufacturing invested; infrastructure was improved; productivity and wages rose. America and China converged. It follows that the gains from trade diminished. This has mostly been at America’s expense. Chinese goods became more expensive relative to domestically produced ones. Meanwhile, because productivity was advancing rapidly, in China the lost gains from trade were compensated for by gains from productivity. This has been replicated on a global scale as the dynamic between developed and less-developed countries. There were massive gains from trade in the early days, and a convergence between the two sides that has seen the biggest ever eradication of extreme poverty. But the gains from trade are now much less. This is one of the reasons that living standards in the developed world have struggled since the mid-2000s; access to ultra-cheap goods from the less developed world has drastically diminished. This development is almost unacknowledged by economists; the late great Paul Samuelson has been to the only one that I have seen to point this dynamic out – largely before it happened. Instead people are bewailing the loss of a system of global trade that delivered so much benefit in the past.
The world has progressed in another way. Manufacturing productivity has advanced steadily, mainly through automation, but also through better process management. This has tilted the balance of developed economies towards services that are largely untradable. This means that the impact of trade on developed economies is steadily diminishing.
This doesn’t mean that gains from trade have disappeared. Surely it still makes sense for Apple to make its iPhones in intermediate economies? But it does mean that strategic considerations are weighing more heavily than commercial ones. In particular both America and China are worrying about what would happen if war broke out between them – an increasing risk given China’s ambitions to absorb Taiwan. It also doesn’t mean that the reordering of manufacturing supply lines that the Trump administration seeks won’t be painful and disruptive for both America and its trading partners – especially those in East Asia. But it does mean that ultimately it will almost certainly be worse for America than anywhere else. I want to talk about the impact on America in more detail in my next post.
But what about trade deficits and surpluses? A current account deficit represents an excess of demand (consumption plus investment) over supply; a trade deficit has a slightly narrower definition – it applies to goods – but it is much the same thing. If demand can’t be met by local supply, you need to imports to make up. This, however, tells you nothing about what caused it. The victim narrative suggests that the surplus of demand arises because domestic supply is being driven out of business by competition from abroad. The economy then runs up debt (or sells its assets to foreigners) in order to maintain demand, which has to be supported by imports, and it all ends in ruin. An alternative, boomtime narrative is that consumers are on a demand binge which domestic supply cannot meet. Foreigners are happy to finance this because this booming economy provides opportunities to make returns. Trump supporters are scarred by the sight of business closures with the excuse of foreign completion being given, or outsourcing to cheaper suppliers abroad, and point to victim narrative. Trump critics point to low US unemployment and a healthy economy, and say that there is no obvious case that the supply side is being suppressed – and so lean to the boomtime narrative.
But there is a further dynamic. Some countries, including Germany and China, enjoy trade and current account surpluses as a matter of policy. They achieve this by, one way or another, suppressing demand so that the supply side can generate a surplus to export. This might be by underpaying their workers and letting businesses accumulate profits; it can be through governments over-taxing and leaving an unspent government surplus; or it can be through a conservative public forever saving for a rainy day. Why do governments let this happen? A surplus means that the country does not require foreign finance, and that generally makes the national finances easier to manage; for dictatorships, like China, that can be especially important. If some countries run a surplus, then others must run a counterpart deficit. This pattern can help fuel the victim narrative of deficits. The alternative view is that surplus countries are selling themselves short – they could charge more for their exports and/or allow their citizens to consume more – and that deficit countries are beneficiaries of this generosity – and should be sending the surplus countries thank you notes. Which narrative (and others are available) better fits the facts depends on the circumstances. One the one hand you might have a colony being exploited by its ruling power; on the other you could have an industrial powerhouse using foreign capital to build up its infrastructure and industrial base. You need to get beyond the raw statistics to work out what is going on.
There is an argument that all trade should be in balance, and persistent surpluses and deficits show distortions from “fair” trade. This comes up quite a bit for people trying to “sanewash” Mr Trump’s actions. He himself seems to have a much cruder understanding: a surplus means you are getting one over on the other side and building up wealth; a deficit means you are being ripped off and seeing your wealth disappear into foreign pockets. The idea that surpluses and deficits may simply be a reflection of supply and demand being out of kilter runs counter to this.
What role do exchange rates play in all this? Exchange rates should adjust to an equilibrium that allows trade and capital flows between countries to balance – letting the market decide. Countries can try to lean on the market by buying or selling reserves – but this only really works to manage short-term blips where governments think the markets are temporarily distorted. Monetary policy, fiscal policy and capital controls all affect the exchange rate, and can be used to fix exchange rates – but ultimately because these policies work because they affect supply and demand, and the capital flows required to finance them. You can get too hung up on asking what a “fair” exchange rate is.
What is the impact of the Trump tariffs on the world economy? In the short term there will be a lot of disruption, and we have only seen the start of it. There are two pressure points that will need close attention. The first is less developed economies that have been slammed with high tariffs: notably Vietnam, Thailand and Bangladesh. These do not have the resilience (or negotiating power) of bigger economies, such as China, Japan or South Korea. They may be able to divert to other markets, but long term damage looks likely. The second is in the financial system; this has been delivered a series of shocks by the Trump administration, of which Liberation Day is merely the biggest. A lot of bets made by intermediaries have gone sour and these could have ripple effects that start to endanger bigger institutions – this is what happened to Liz Truss’s government in the UK in 2023, causing its demise. A danger sign is that the price of safe haven assets, such as US Treasuries, has been sinking alongside riskier ones. An added risk is if China starts to dump its some of its substantial holdings of US Treasuries – which it might need to do to counter the disruption of trade. A new financial crisis might develop.
But this crisis is not the end of globalisation: it simply marks exit, or intended exit, of the US as a global trading power. The rest of the world can carry on trading more or less freely with itself – and that seems to be what they want to do. And in some respects America will continue as a global commercial power: Google, Meta, Apple, Microsoft and even Amazon will be disrupted but there is no fundamental threat to their business models. The globalisation of information will go on. The big question is who, if anybody, will take up America’s leadership role? China could curb its own tendency to bully; the European Union could have its moment.
In due course, however, I expect the Trump tariff regime will collapse, and America will come back into the world system as a diminished player. But that’s another story.
First published on Substack on 9 April 2025