The aggregate production function and the measurement of technical change : not even wrong This is an extremely important and long awaited book. The authors provide a cogent guide to all that is wrong with the theory and empirical applications of the discredited notion of an aggregate production function. Their critique has devastating implications for orthodox macroeconomics. (Anwar Shaikh New School for Social Research US).  There are none so blind as those who will not see. For decades now John McCombie and Jesus Felipe have been publishing papers which draw out the implications of the conceptual vacuousness that characterises fitting aggregate production function specifications to data to test the validity of the marginal productivity theory of distribution a critique first developed by Henry Phelps Brown and Herbert Simon. By careful empirical and theoretical work they have reached the conclusion that the huge literature on aggregate production functions and technical progress is not even wrong because predictions cannot be tested that they are only variations on manipulations of national accounting identities. Perhaps this time it really will be different the scales will fall from the professions eyes. I certainly hope so. (G.C. Harcourt Jesus College Cambridge UK and University of New South Wales Australia). This is a very important book. Proofs that aggregate production functions do not exist have been around for more than 50 years. This casts doubt not only on macroeconomic theory but also on empirical work and policy. Yet this has not deterred macro economists. The authors show in great detail that the apparent fit of such functions to value based data is a tautology and not a proof that such aggregates exist. One hopes that the profession will finally take note. (Franklin M. Fisher Massachusetts Institute of Technology US). Felipe and McCombie have gathered all of the compelling arguments denying the existence of aggregate production functions and showing that econometric estimates based on these fail to measure what they purport to quantify: they are artefacts. Their critique which ought to be read by any economist doing empirical work is destructive of nearly all that is important to mainstream economics: NAIRU and potential output measures measures of wage elasticities of output elasticities and of total factor productivity growth. (Marc Lavoie University of Ottawa Canada).