When the Black Lives Matter (BLM) protests spilled over from America to the UK in the Spring of 2020, they initially had a strong copy-and-paste character. Although the murder of George Floyd had nothing to do with Britain, and although Britain and America are not especially similar in terms of race relations, BLM-inspired protests in the UK were initially an almost exact replica of the American original.

But in the subsequent months, they developed a marked country-specific element: they led to a renewed focus on Britain’s imperialist past.

This became most obvious when a group of BLM protestors in Bristol pulled down a statue of Edward Colston, a 17th century merchant who had made a fortune in the slave trade. At a similar protest in London, activist sprayed the word “racist” on the Winston Churchill statue on Parliament Square. Meanwhile in East London, a statue of Robert Mulligan, another merchant and slave trader, was preemptively removed to avoid a repetition of the Bristol scene.

In this more extreme form, progressive iconoclasm did not catch on. Fears that Britain would soon be run by a “woke Taliban”, tearing down everything that reminded them of Britain before the “Great Awokening”, did not materialise. But in more subtle ways, the practice of altering cityscapes and public spaces in line with current ideological fashions very much did catch on. Three years later, the Guardian reported that the names of 39 streets, buildings and schools had been changed, while 30 statues, plaques and other memorials had been removed or altered. This is an ongoing process. As an organisation, BLM are now mostly defunct, but then — they are no longer needed. Their work is done. The ideology they represent is now thoroughly embedded in major public, private and third-sector institutions.

It is therefore important to understand this ideology. For woke progressives, Britain’s imperialist past is not simply a lamentable aberration from an otherwise positive national story. Instead, they see it as the very foundation on which modern Britain is built. For them, the past is not really “the past” at all. It is still very much alive, and shapes the present.

They subscribe to a popularised, “wokified” version of what economic historians call the “Williams Thesis”. Eric Williams was an Oxford academic, and the first post-independence prime minister of Trinidad and Tobago. In 1944, he wrote an influential book called “Capitalism and Slavery”, in which he claimed that the profits from the slave trade made a major contribution to financing Britain’s Industrial Revolution. Williams never said that this was the only factor which explains Britain’s rise to an industrial superpower, or that the Industrial Revolution could not have happened otherwise. But as is often the case when such ideas get popularised, the subtleties get lost in translation. Today, a typical Guardian article on the subject will simply say that Western capitalism was “built on” slavery and colonial exploitation.

You can see why this version of the Williams Thesis has such a strong appeal to sections of the British Left. It is an “original sin” story of modern Britain and the West, which also doubles up as an original sin story of capitalism. It leads to a fusion of the two most fashionable ideologies of our time, namely, woke progressivism and anti-capitalism.

But is it actually true? How important were colonial empires for the economic development of Britain and other Western countries?

This is the question I try to answer in my new book “Imperial Measurement. A Cost-Benefit Analysis of Western Colonialism”. The short answer is: probably not very, and quite possibly not at all.

I am hardly the first person to say that: I am merely rediscovering a very old tradition of liberal anti-imperialism. Already in the 18th and 19th centuries, some prominent thinkers believed that the Empire would fail a basic cost-benefit test. Adam Smith argued in 1776 that“Great Britain derives nothing but loss from the dominion which she assumes over her colonies”, and in 1835, Richard Cobden described the colonies as “a severe burden to the people of these realms”, as well as “the costly appendage of an aristocratic government”.

More precisely, liberal anti-imperialists in the Smith-Cobden tradition believed that the additional military expenditure required to sustain the Empire exceeded the gains from imperial trade, and that those gains did not depend on the existence of the Empire anyway. In the absence of an Empire, free or free-ish trade between sovereign nations would replace enforced imperialist trade relations.

With the benefit of hindsight, access to better data, and the ability to draw on academic research that has been carried out since, I revisit these old arguments, and conclude that the early critics of the Empire were broadly correct. Empires really are expensive to defend, maintain and administer. To forge trade links, empires are neither necessary nor sufficient. More recent empirical studies suggest that empires deepened trade relations between its constituent parts, so the Smith-Cobden view that Britain could have traded on similar terms without an empire may have been a bit too optimistic. But these studies also find that empires were far from the only factor. Britain traded with plenty of places that it never colonised, and at least some of the trade between Britain and, say, India would have taken place anyway, even if India had never been a British colony.  

Britain’s most important trading partners were other industrialising Western economies, not the colonies

In any case, overseas trade and investment were not nearly as important for the British economy then as they are now. They could not have been. The technologies that underpin modern-day trade volumes, such as container shipping, were not invented until the second half of the 20th century. Before then, the bulk of economic activity was domestic, and while trade obviously mattered, Britain’s most important trading partners were other industrialising Western economies, not the colonies.

At least in its current, extreme interpretation, the Williams Thesis is almost certainly false. But it fits very neatly into our woke, anti-capitalist zeitgeist. Which is why, for now, it is here to stay.