Marx wrote to Engels, in 1862, that in all quarrels with the statisticians, he found the theoreticians had ‘always been in the wrong’. Rob Bryer is one of those few accomplished theoreticians who takes due account of statistical method and in particular accounting, to which Marx paid scrupulous attention. In a convincing and refreshing work, Bryer throws new and much-needed light on Marx’s theory of economics, of value, and his profound understanding of the way business works.