Le multiplicateur d’investissement public. Une revue de littérature

This article gives a summary of the results of the main studies of the impact assessment of public expenditure and in particular of public investment. This assessment is carried out in three successive points: (1) Since public investment is primarily a component of demand, we have first looked at its effectiveness in terms of general public spending. The literature leads to a multiplier of public spending on GDP of 0.8 on average, with great variability in the results. (2) Second, the productive dimension of public investment is integrated. The economic literature manages to establish that, in the long run, revival by investment is superior to classical expenditure. On the other hand, the literature tends to underline this superiority in terms of the short-term revival of public consumption over new public infrastructure projects, whose implementation times would be very long. (3) Finally, as the current debate on a spending stimulus is occurring in a context of economic crisis, the article shows that in the literature the multiplier increases in times of crisis to high values of between 1.3 and 2.5. In addition, the result observed in normal times is reversed: a recovery via major public investment projects is stronger than through public consumption. JEL codes: E27, E62, H54