I've been thinking about it and, unless I understand it wrong, it seems to be wrong, no?
The USA, the main imperialist country (according to Leninists) imports more capital than it exports.
https://tradingeconomics.com/united-states/capital-flowsFurthermore, it seems to me that the underdeveloped world is not kept permanently underdeveloped. Somehow, the various national bourgeoisie in countries such as China, India (to a lesser extent) have become competitive with western capital (I suspect due to the sheer mass of labor-power) and are now themselves exporting capital into, say, Europe. This general tendency for the rest of the world to become more developed, with more infrastructure, a more significant national bourgeoisie everywhere seems to me to have falsified Lenin's theory of imperialism, which would mean that underdeveloped countries should remain permanently underdeveloped.
https://wir2022.wid.world/chapter-2/, figure 2.4 shows inequality between countries are decreasing. I think it's because of the development of China and India. Now, obviously, income inequality isn't a good measurement for Marxists, but I'm not sure if there is any data with which we could discover the rate of exploitation.
In the past, political economists understood the interest rate to be a kind of an indirect way to assess the rate of profit, and since profit arises from the exploitation of surplus value, we could look at that for a possible comparison.
https://www.gutenberg.org/files/38194/38194-h/38194-h.htm#BOOK_I>But the rate of profit does not, like rent and wages, rise with the prosperity, and fall with the declension of the society. On the contrary, it is naturally low in rich, and high in poor countries, and it is always highest in the countries which are going fastest to ruin.https://tradingeconomics.com/country-list/interest-rateChina has a 3% interest rate, the USA 4.5% and Germany 2.15%.
It's possible Adam Smith was critiqued by Marx somewhere and I overlooked it. But I'm curious to hear your thoughts on this.
I think in classical Marxist theory, however, the establishment of one world market is inevitable, with all old structures and the global migration of capital etc. leading to that. And is that not what we've seen with NAFTA, the EU and so on?