Thanks for the engaged discussion, I am not an economist but find this fascinating to learn about. My understanding is that paper's key point is the higher the

Thanks for the engaged discussion, I am not an economist but find this fascinating to learn about. My understanding is that paper's key point is the higher the absolute economic output the larger fraction of that output can be re-invested in efficiency/technological improvements, which compounds over time and leads to increasing gaps between different countries. Did I get that right even if very simplified? I'd also be curious to read De Long's most recent book since he says he has significantly changed his opinions in the intervening 30 years and has swung significantly leftwards. As for the issue of comparing Mississippi and Germany, backing out state-level vs US growth for comparison adds some challenge, but best I can figure for the period since 1997 that I can find data, they both have roughly the same 1.4x real GDP growth, which lags the US at 1.7x. I still take issue with the implication that Germany is somehow doing worse than Mississippi, but agree the US is clearly doing better at growing in absolute terms. Why are you confident HDI is "certainly not" a better comparison than GNI? You seem to imply that comparing achieved education levels is a bad thing or worthless? Life expectancy is confounded by population-level differences, but I would be surprised though to learn that genetic predisposition to diabetes/obesity accounts for a majority of the difference in life expectancy. In particular, diabetes rates in MS have been increasing rapidly over the last decade but falling in Germany, much more than genetic pool changes would account for. That points to environmental causes - access to healthcare, nutrition, etc.. which are very much within the abilities of the state to impact.