If one can ascribe a coherent worldview to U.S. President Donald Trump, it is that it's all about him. That is, everything that happens on this Earth, or at the very least in the United States, is his doing if it's good and a personal affront to him if it's bad.
After two years during which things generally went well, and the president claimed credit for it, it is thus only natural to see this month's stock market sell-off as a referendum on Trump. But while the president's overly personalized reaction to the downturn may have worsened the market turmoil and could conceivably even unleash an actual crisis — more on that in a moment — it's worth contemplating what else could be driving it. Here are a few obvious candidates.
Stocks were really expensive. Economist Robert Shiller's cyclically adjusted price-earnings ratio — the Standard & Poor's 500 Index divided by the past 10 years of earnings — topped 33 last January, the only time that has happened outside the stock market bubble of 1997 to 2001. Now they're cheaper but still well above long-run averages.