Donald MacKenzie

There’s a limit to how much you can learn while sitting at your desk reading the footnotes to balance sheets. Sometimes, a short seller has to become a field worker. Look at the website of Muddy Waters Research, for example, and notice the attention it pays to the physical world: precipitous, hairpin mountain roads down which huge volumes of timber would have to be hauled; satellite images of the possibly crumbling walls of a giant opencast mine; a solitary lorry idling outside what one might have expected to be a busy factory.

The​ VIX, or Volatility Index, is Wall Street’s fear gauge. I first started paying attention to it in the late 1990s. Back then, a level of around 20 seemed normal. If the index got to 30, that was an indication of serious market unease; over 40 signalled a crisis. The highest the VIX ever got was during the 1987 stockmarket crash, when it reached 150. In the 2008 global banking...

Sometimes,​ the most important – and perturbing – insights make their way into the world without fanfare. As yet, few have picked up on an analysis by the New York University economist Thomas Philippon of the history of the unit cost of financial intermediation. The unit cost is a measure of the efficiency of the financial system, and Philippon tracks its level in the United...