However you explain it, the fact that leading economies like the U.S. are increasingly reliant on consumption to drive economic growth is a worrying sign.

A new study from the Bank for International Settlements found that periods of consumption-led growth, defined as when private consumption grows more quickly than overall growth, tend to show both sluggish growth and weak increases in investment and net exports.

"Increasing shares of private consumption in GDP can be a leading indicator of future growth slowdowns, particularly if consumption-led expansions come on the back of growing imbalances and rising debt burdens," Enisse Kharroubi and Emanuel Kohlscheen of the BIS, the central bank of central banks, said in the study.

The study, which looked at a range of developed and emerging market economies, found that if you measure over three years, annualized GDP growth is just 1.9 percent during consumption-led periods compared with 2.6 percent when the rest of the economy led the way.

Looking at the past 20 years, particularly in the U.S., you can construct an argument that we find ourselves overly relying on consumption because we are constrained by less favorable demographics and the erosion of middle-income buying power. This may have encouraged monetary policymakers to encourage the only growth they felt was available: consumption-led.

But high debt levels can impair future growth. We may have found ourselves in the great financial crisis precisely because of this, and because globalization and trade patterns combined to suppress income growth for most households.

Following on the brief dot-com euphoria, the recession in the early years of the millennium was arrested in part because the Federal Reserve kept rates too low. This boosted investment in housing. That put some people to work building and improving houses, and drove house prices higher, which allowed some people to boost their consumption by taking cash out of their now more valuable house.

Sadly, but inevitably, the housing bubble and credit orgy led to a destructive and debilitating financial crisis. Although you can hardly blame them, the medicine applied to this crisis by central bankers, first very low rates and then the addition of quantitative easing, was very much like the loose money that helped the bubble inflate.

James Saft writes for Reuters.