Yes, Soddy’s economic insights are valid, and Douglas’s even deeper insights into the monopolistic paradigms by which the business model of finance dominates all other business models and 90+% of the general populace have been incorrectly characterized and shunted aside. The latter is most often lumped in with the “interest is the entire problem” cranks when the actual problem it exposes is the systemic rate of flow of total costs (of which interest is merely a subset) in ratio to the rate of flow of total individual incomes. It is important to recognize the difference, and also to understand that Douglas was not a general equilibrium theorist nor an advocate of austerity, and that his recognition that the monopolistic paradigms of finance were the real and deepest economic problem was way ahead of his contemporary Keynes and even of current leading edge heterodox economists who still have not come up with policies that would break up that monopoly and reverse the above problematic ratio.