For 20 years, the divergence debate has dominated global economic history. Although interest in the origins of modern world inequality dates further back, the recent discussion engaged a bigger range of theoretical perspectives than before and involved more novel kinds of data. Patrick O’Brien contributed to broadening the scope of the debate, with ground-breaking work done on the origins and meaning of globalization, state formation in the east and the west, and measurement of standards of living. More than shaping the discourse on international inequality, O’Brien facilitated it by leading the forum called Global Economic History Network, which encouraged many economic historians to think globally.
Interest in the divergence debate seems to be fading. Perhaps all arguments are fated to run into diminishing returns sooner or later. In my view, its premises were problematical too. Its central question – why average incomes in some countries or nations grew faster than in others between 1820 and 1950 – smuggled two questionable assumptions. First, countries had existed as the same countries for hundreds of years. And second, the growth experience of regions like India or China can be summed up in average incomes. Both these premises oversimplify regional history. With such doubtful foundations as these, the drive to fit individual regions into grand global narratives of growth and international inequality produced some outlandish works along with some stimulating ones.
A particular problem with fitting regional history within a narrative of world inequality is how we handle inequality within nations or regions. The problem is this. If the society in any country is unequal and becomes more unequal, an average income would not be a good reflection of what happened there. Nor would divergence between nations mean anything because some livelihoods in the country would have fallen behind the world, and others caught up with it. By comparing average national incomes and implicitly identifying each country with a particular set of institutional, cultural, or political conditions, we would know nothing about what causes growth and why stagnation persists.
In the historiography of Indian development, a global Marxist account of long-run development addressed and solved this problem. It brought intraregional inequality and international inequality into a compatible relationship by suggesting that growing inequality within India was a symptom of a mechanism that also made India's average income fall behind the world’s.