Too Much Finance? By Jean-Louis Arcand, Enrico Berkes, and Ugo Panizza
IMF Working Paper No. 12/161
Summary: This paper examines whether there is a threshold above which financial development no longer has a positive effect on economic growth. We use different empirical approaches to show that there can indeed be "too much" finance. In particular, our results suggest that finance starts having a negative effect on output growth when credit to the private sector reaches 100% of GDP. We show that our results are consistent with the "vanishing effect" of financial development and that they are not driven by output volatility, banking crises, low institutional quality, or by differences in bank regulation and supervision.
In this paper we use different datasets and empirical approaches to show that there can indeed be “too much” finance. In particular, our results show that the marginal effect of financial depth on output growth becomes negative when credit to the private sector reaches 80-100% of GDP. This result is surprisingly consistent across different types of estimators (simple cross-sectional and panel regressions as well as semi-parametric estimators) and data (country-level and industry-level). The threshold at which we find that financial depth starts having a negative effect on growth is similar to the threshold at which Easterly, Islam, and Stiglitz (2000) find that financial depth starts having a positive effect on volatility. This finding is consistent with the literature on the relationship between volatility and growth (Ramey and Ramey, 1995) and that on the persistence of negative output shocks (Cerra and Saxena, 2008). However, we show that our finding of a non-monotone relationship between financial depth and economic growth is robust to controlling for macroeconomic volatility, banking crises, and institutional quality.
Our results differ from those of Rioja and Valev (2004) who find that, even in their “high region,” finance has a positive, albeit small, effect on economic growth. This difference is probably due to the fact that they set their threshold for the "high region" at a level of financial depth which is much lower than the level for which we start finding that finance has a negative effect on growth.
Our results are instead consistent with the vanishing effect of financial depth found by Rousseau and Wachtel (2011). If the true relationship between financial depth and economic growth is non-monotone, models that do not allow for non-monotonicity will lead to a downward bias in the estimated relationship between financial depth and economic growth.