… is from page 63 of Deirdre McCloskey’s 1987 monograph, Econometric History (links added):
[Robert Paul] Thomas, in short, had turned the story on its head: like the second empire, bejeweled with India, the first British empire was in economic perspective no great burden on the colonies. Quite possibly it was a benefit; and it was very likely a burden on Britain itself. Thomas, and Philip Coelho [1973], extended the calculations to the jewel of the first empire, Jamaica. Take it as given that the quarrelsome yeomen of the mainland colonies were not profitable subjects; this might be expected. But surely one would expect that the slaves and supervisors of the Caribbean plantations would have been profitable. Surely Britain got more than it gave from Jamaica. Yet it was not so. Jamaican sugar sold in Britain at higher prices than it fetched on world markets. The owners of Jamaican plantations, being a notoriously effective lobby in Parliament, gained much from the British link; but the great British public did not. Imperialism was a subsidy for colonials.