A few weeks have passed since I've updated my overview of personal consumption from the Consumer Metrics Institute (CMI), so let's have a fresh look in advance of Friday's revised GDP. I'll start with an overlay since 2010 of the CMI Weighted Composite and Growth Indexes.
[Click all to enlarge]
Background
For those unfamiliar with these data series, here is a link to the Institute's website. Its page of frequently asked questions is an excellent introduction to the service. See also the Institute's March 22 commentary, News and the Consumer, Reflections on Chernobyl and the Economy.
The charts below focus on the "Trailing Quarter" Growth Index, which is computed as a 91-day moving average for the year-over-year growth/contraction of the Weighted Composite Index, an index that tracks near real-time consumer behavior in a wide range of consumption categories. The Growth Index is a calculated metric that smooths the volatility and gives a better sense of expansions and contractions in consumption.
The 91-day period is useful for comparison with key quarterly metrics such as GDP. Since the consumer accounts for over two-thirds of the U.S. economy, one would expect that a well-crafted index of consumer behavior would serve as a leading indicator. As the chart suggests, during the five-year history of the index, it initially lived up to that expectation. Actually, the chart understates the degree to which the Growth Index leads GDP.
Why? Because the advance estimates for GDP are released a month after the end of the quarter in question, so the Growth Index lead time has been substantial. However, over the past several months the correlation has disappeared. One speculation is that the Federal Reserve intervention with the rumor and subsequent reality of QE2 has stimulated the economy for the time being, but not the consumer.
Has the Growth Index also served as a leading indicator of the stock market? The next chart is an overlay of the index and the S&P 500. The Growth Index clearly peaked before the market in 2007 and bottomed in late August of 2008, over six months before the market low in March 2009.
The most recent peak in the Growth Index was around the first of September, 2009. Since its peak, the Growth Index declined dramatically. It remains in contraction territory although the contraction has become less severe. In contrast, the market continued its rally to late April 2010, corrected during the summer months, and then returned to the neck-snapping velocity of the spring 2009 rate of recovery.
It's important to remember that the Growth Index is a moving average of year-over-year expansion/contraction whereas the market is a continuous record of value. Even so, the pattern is remarkable.
The next chart compares the contraction that began in 2008 with the one that began in January of this year. I've added annotations for the elapsed time and the relationship of the contractions to major market milestones.
Does the CMI Growth Index Provide A Comprehensive Snapshot of the U.S. Consumer?
In January Rick Davis, the founder of the Institute, issued an important report on interpreting the index data: Reflecting Back on 2010 [pdf]. Davis essentially concludes that the index data is skewed toward a demographic of consumers who were more vulnerable to the economic downturn than the population as a whole:
By the third quarter we began to understand that the demographics of the consumers most likely to buy on-line were the same as those households most severely impacted by the recession. Unwittingly, some of the previously identified sampling biases in our data collection methodologies turned out to be much more significant than we might have suspected. Simply put, young and highly educated members of generations "X" and "Y" were particularly vulnerable to the hallmarks of this recession: Entry level job losses and vanishing home equity.
In sum, we can't take the CMI Growth Index as an indicator of the consumer economy as a whole, but it clearly offers important insight into the health of the consumer. In fact, it is a demographic segment on which the future of the economy will become increasingly dependent. It seems difficult to imaging a sustained business cycle and long-term economic recovery while the CMI demographic sweet-spot sputters in a year-over-year contraction.
