One of Turchin's most prominent fields of research is his study of the hypothesis that population pressure causes increased warfare. Turchin, in collaboration with Korotayev, has shown that negative results do not falsify the population-warfare hypothesis.[5] Population and warfare are dynamical variables. If their interaction causes sustained oscillations, then we do not in general expect to find strong correlation between the two variables measured at the same time (that is, unlagged). Turchin and Korotayev have explored mathematically what the dynamical patterns of interaction between population and warfare (focusing on internal warfare) might be in stateless and state societies. Next, they tested the model predictions in several empirical case studies: early modern England, Han and Tang China, and the Roman Empire. Their empirical results have lent support to the population-warfare theory: Turchin and Korotayev have found that there is a tendency for population numbers and internal warfare intensity to oscillate with the same period but shifted in phase (with warfare peaks following population peaks). Furthermore, they have demonstrated that the rates of change of the two variables behave precisely as predicted by the theory: population rate of change is negatively affected by warfare intensity, while warfare rate of change is positively affected by population density.[5]
In 2010 Turchin published research using 40 combined social indicators to predict that there would be worldwide social unrest in the 2020s.[8][9] He subsequently cited the success of Donald Trump's 2016 presidential campaign as evidence that "negative trends seem to be accelerating" and that there has been an "unprecedented collapse of social norms governing civilized discourse".[10] In 2020, Turchin and Jack Goldstone predicted that political and civic unrest in the United States would continue regardless of the party in power until a leader took action to reduce inequality and improve the social indicators that are tracked in their research.[11]
Turchin has published over 200 scientific articles (including more than a dozen in Nature, Science, or PNAS) and at least eight books. He is the founder of the journal, Cliodynamics, "...dedicated to 'the search for general principles explaining the functioning and dynamics of historical societies'",[2] and manages a blog, Cliodynamica.[12]
Turchin, Peter (2023). End Times: Elites, Counter-Elites and the Path of Political Disintegration. Allen Lane. ISBN978-0241553480.
Turchin, Peter; Hoyer, Daniel (2020). Figuring Out the Past; The 3,495 Vital Statistics that Explain World History. Economist Books. ISBN9781541762688.
Turchin, Peter (1998). Quantitative Analysis of Movement: Measuring and Modeling Population Redistribution in Animals and Plants. Sinauer Associates. ISBN978-0878938476.
Turchin, P. (2009), "Long-term population cycles in human societies"(PDF), in Ostfeld, R. S.; Schlesinger, W. H. (eds.), The Year in Ecology and Conservation Biology, 2009, pp. 1–17, archived from the original(PDF) on 2011-07-21, retrieved 2009-08-26
Turchin, P.; Taylor, A. D. & Reeve, J. D. (1999), "Dynamical role of predators in population cycles of a forest insect: an experimental test", Science, 285 (5430): 1068–1071, doi:10.1126/science.285.5430.1068, PMID10446053
Goldstone, Jack A.; Turchin, Peter (September 10, 2020). "Welcome To The 'Turbulent Twenties'". Noema Magazine. Berggruen Institute. Retrieved 22 November 2020.
Osnos, Evan, "Ruling-Class Rules: How to thrive in the power elite – while declaring it your enemy", The New Yorker, 29 January 2024, pp. 18–23. "In the nineteen-twenties... American elites, some of whom feared a Bolshevik revolution, consented to reform... Under Franklin D. Roosevelt... the U.S. raised taxes, took steps to protect unions, and established a minimum wage. The costs, Turchin writes, 'were borne by the American ruling class.'... Between the nineteen-thirties and the nineteen-seventies, a period that scholars call the Great Compression, economic equality narrowed, except among Black Americans... But by the nineteen-eighties the Great Compression was over. As the rich grew richer than ever, they sought to turn their money into political power; spending on politics soared." (p. 22.) "[N]o democracy can function well if people are unwilling to lose power – if a generation of leaders... becomes so entrenched that it ages into gerontocracy; if one of two major parties denies the arithmetic of elections; if a cohort of the ruling class loses status that it once enjoyed and sets out to salvage it." (p. 23.)
