ACL-2International audienceIn order to examine productivity waves and convergence processes, we study productivity trends, trend breaks, and levels for 13 advanced countries between 1890 and 2012. We highlight two productivity waves, a big one following the second industrial revolution and a smaller one following the ICT revolution. The convergence process has been erratic, halted by inappropriate institutions, technology shocks, financial crises, and above all wars, which led to major productivity level leaps, downwards for countries experiencing war on their soil, and upwards for other countries. Productivity trend breaks have been identified following wars, global financial crises, global supply shocks, and major policy changes. The upward trend break for the U.S. in the mid-1990s has been confirmed, as has the downward trend break for the euro area in the same period

We identify two counteracting effects of credit access on productivity growth: on the one hand, better access to credit makes it easier for entrepreneurs to innovate; on the other hand, better credit access allows less efficient incumbent firms to remain longer on the market, thereby discouraging entry of new and potentially more efficient innovators. We first develop a simple model of firm dynamics and innovationbased growth with credit constraints, where the above two counteracting effects generate an inverted-U relationship between credit access and productivity growth. Then we test our theory on a comprehensive French manufacturing firm-level dataset. We first show evidence of an inverted-U relationship between credit constraints and productivity growth when we aggregate our data at the sectoral level. We then move to firm-level analysis, and show that incumbent firms with easier access to credit experience higher productivity growth, but that they also experience lower exit rates, particularly the least productive firms among them. To support these findings, we exploit the 2012 Eurosystem's Additional Credit Claims programme as a quasi-experiment that generated an exogenous extra supply of credits for a subset of incumbent firms.

The productivity slowdown has been analysed as an effect of weaker technological progress, of the digital economy or of a less efficient reallocation process. Using data on firms operating in France, we highlight that, at the technological frontier, productivity has accelerated, especially over the recent period, which contradicts the hypothesis of a decline in innovation. The most productive firms in a given year do not, however, improve their relative advantage. The convergence of firms' productivity does not seem to have slowed down in the 2000s, which does not confirm the hypothesis of a decrease in the dissemination of innovation. On the other hand, the dispersion of productivity between firms has increased, which suggests growing difficulties in reallocating production factors, labour and capital, between firms.

Two different approaches are used in this article to study productivity per employee: the determinants of its growth rate in the 1990s are first examined, and then the determinants of its level, using a more structural approach. ICT are shown to have a positive and significant effect on both growth rates and levels of productivity. This result is consistent with that of Gust and Marquez (2002), although the sample of countries is larger and GMM are used. In both sections of the paper, the employment rate and productivity exhibit a significant negative relationship, arising from the concentration of employment on the most productive members of the workforce. Indicators of financial depth and price stability are found to be significant.

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