16/5/19: Identifying Debt Bubble 4.0

Having just posted on the debt supercycle-related comments from Gundlach (https://trueeconomics.blogspot.com/2019/05/16519-gundlach-on-us-economy-and-debt.html), here is a chart identifying these super-cycles in the U.S. economy:

The periods of significant leverage in the U.S. economy have been identified as follows:

• First, I took nominal GDP growth rates (q/q) snd nominal total non-financial debt growth rates (also q/q) for the entire period of data coverage for which all data points are available (since 1Q 1966). 
• Second, I adjusted nominal non-financial debt growth rates to reflect the evolving ratio of debt to U.S. GDP.
• Third, I subtracted adjusted debt growth rates from nominal GDP growth rates to arrive at change in leverage risk direction. This is the difference figure shown in the chart below. Positive numbers reflect quarters when GDP growth rate exceeded growth in GDP-ratio-adjusted debt and are periods of deleveraging in the economy, and negative periods correspond to the situation where GDP growth rate was exceeded by GDP-ratio-adjusted growth rate in debt.
• Fourth, I calculated 99% confidence interval for historical average difference (shown in the chart below).
• Fifth, I identified three regimes of debt evolution: Regime 1 = "Deleveraging" corresponds to the Difference variable being non-negative (periods where the gap between growth rate in GDP and growth rate in debt is non-negative); Regime 2 = "Non-significant leveraging up" corresponds to periods where the gap (difference) between GDP growth rate and debt growth rate is between zero and the lower bound of the confidence interval for historical average difference; and Regime 3 = "Significant Leveraging up" corresponds to the periods where statistically-speaking, the negative gap between growth in GDP and growth in debt is statistically significantly below the historical average.

I highlighted in the above chart four periods of significant, persistent leveraging up, identified as Debt Bubbles 1-4. There is absolutely zero (statistical) doubt that the current period of economic recovery is yet another manifestation of a Debt Bubble. And, given the composition of the debt increases since the end of the Global Financial Crisis, this latest Bubble is evident across all three components of non-financial debt: the households, corporates and the U.S. Federal Government.