Mahalanobis wasn’t alone in his faith in the computer’s ability to transform economic management. At least two very prominent economists, Oskar Lange and Nobel laureate Tjalling Koopmans, suggested that computers provided a solution to the computational complexities of centralised economic planning. This was part of a major debate among economists, referred to as the economic calculation or socialist calculation debate. In the interwar years, advocates of mostly unregulated capitalism such as Ludwig von Mises, Friedrich Hayek and Lionel Robbins argued that planned economies were fundamentally incompatible with efficient resource allocation because they spurned the only instrument that guaranteed it — the market’s famed invisible hand. The socialist economist Oskar Lange responded that ‘rational economic accounting’ was certainly possible under socialism since planners only needed to solve a series of simultaneous equations. Hayek retorted that since making thousands of such calculations in any reasonable timeframe was impossible, efficient planning was a chimera. But the invention of the computer changed the debate, according to Koopmans and Lange. The latter saw vindication for socialist planning in the computer. As he put it, ‘My answer to Hayek and Robbins would be: so what’s the trouble? Let us put the simultaneous equations on an electronic computer and we shall obtain the solution in less than a second.’ Mahalanobis, it appears, was a silent partisan.