Modelling the past to predict the future

Guardian readers respond to Laura Spinney’s long read on quantitative approaches to history. Laura Spinney’s important, excellent long read ( Calculating the future, 12 November) draws attention to the developments in quantitative approaches to history pioneered by Jack Goldstone and Peter Turchin, including the journal Cliodynamics, and their predictive possibilities. She could have mentioned the predictive success of Turchin’s quantitative approach (including modelling the ri