How do scholars weigh colonialism's legacy, and why do they disagree?

They weigh it differently because the evidence is real but incomplete, and because the question mixes facts with values. There is no single verdict among scholars. An extensive body of literature has examined the legacy of colonialism on economic outcomes in Africa, with numerous studies showing disputed economic effects.

Some historians stress harm. Walter Rodney argued that the decisive effect of colonialism was that Africa lost power. Caroline Elkins has argued against seeing the British Empire as primarily liberalising and modernising, criticising its widespread use of violence and emergency laws. Amartya Sen and others assert that British policies worsened the famines in India that killed millions.

Others stress benefit. Niall Ferguson calculates that the economic and institutional development the British Empire brought resulted in a net benefit to its colonies. And some historians treat the legacy as varied and ambiguous: roads and railways were built, but, according to critics, mainly for extraction; and one meta-analysis of 18 African countries found that a third of them grew faster after independence.

The argument is not only about the past. Economists such as Acemoglu, Johnson and Robinson argue that institutions explain why some former colonies did better than others. Borders drawn by colonial powers did not always match ethnic or religious lines, and most African colonies decided in 1964 to keep them anyway, fearing civil war.

The honest answer is that a fair account has to say who is making each claim, what evidence they use and what they leave out.