Howard Marks put it nicely when he said that, rather than worrying about share price volatility, ‘The possibility of permanent loss is the risk I worry about… and every practical investor I know worries about.’ So it seems the smart money knows that debt – which is usually involved in bankruptcies – is a very important factor, when you assess how risky a company is. We can see that Waste Management, Inc. (NYSE:WM) does use debt in its business. But the real question is whether this debt is…