Secular bipolar growth rate of the real US GDP per capita: implications for understanding past and future economic growth

TL;DR

This paper analyzes the US GDP per capita growth fluctuations over two centuries, revealing a bimodal regime-switching pattern that explains the stable long-term growth rate and has implications for understanding economic cycles and crises.

Contribution

It introduces a wavelet-based method to characterize GDP growth regimes and links these patterns to social bubble theory, offering new insights into economic growth dynamics and crisis impacts.

Findings

GDP growth distribution is bimodal, with switches between high and low regimes.

Long-term average growth rate remains stable due to regime compensation.

2008 crisis effects may be overestimated due to regime dynamics.

Abstract

We present a quantitative characterisation of the fluctuations of the annualized growth rate of the real US GDP per capita growth at many scales, using a wavelet transform analysis of two data sets, quarterly data from 1947 to 2015 and annual data from 1800 to 2010. Our main finding is that the distribution of GDP growth rates can be well approximated by a bimodal function associated to a series of switches between regimes of strong growth rate $\rho_\text{high}$ and regimes of low growth rate $\rho_\text{low}$. The succession of such two regimes compounds to produce a remarkably stable long term average real annualized growth rate of 1.6\% from 1800 to 2010 and $\approx 2.0\%$ since 1950, which is the result of a subtle compensation between the high and low growth regimes that alternate continuously. Thus, the overall growth dynamics of the US economy is punctuated, with phases of strong growth that are intrinsically unsustainable, followed by corrections or consolidation until the next boom starts. We interpret these findings within the theory of "social bubbles" and argue as a consequence that estimations of the cost of the 2008 crisis may be misleading. We also interpret the absence of strong recovery since 2008 as a protracted low growth regime $\rho_\text{low}$ associated with the exceptional nature of the preceding large growth regime.