I read the newspaper article and have been in a lot of contact with the author, we agree on many points, especially that higher poverty lines are needed to track what is happening and that it is surely not enough to look at extreme poverty. But low poverty lines are needed so that we see what is happening to world's poorest. One of the biggest failures of development over the last decades is that incomes of the very poorest on the planet have not risen: https://voxeu.org/article/assessing-progress-poorest-new-evi... This is not widely known because the extreme poverty line is not low enough to focus on what happens to the very poorest. So overall I think it is very important that we keep track of what happens relative to different poverty lines (and we do https://ourworldindata.org/poverty-at-higher-poverty-lines) On the particular point you emphasize, that historians have a poor understanding of poverty and prosperity in the past I do not agree that it is a 'reckless extrapolation of sketchy sources'. I think this is overstating the existing uncertainties and it's not a fair description of the careful and tedious work that historians do. And we did respond to it here https://ourworldindata.org/extreme-history-methods and go in some detail of this historical work. We understand our job as providing access to good, existing research and so our job is to understand the research that is out there and bring it together on the web to make it possible for everyone to understand it, and access it. A very thorough book on what we know about poverty, including the historical decline of the share living on less than an extremely low poverty threshold, is Martin Ravallion's 'The Economics of Poverty: History, Measurement, and Policy'. Let me know what you think!