Here is my Z$2c... Firstly, I don't like generalizations in this particular area. I don't think the last 100 years are necessarily a good guide to the current/upcoming 100 years, especially where bonds are concerned. Secondly, I also think that the one of the most important determinants of future return of an asset is its current price. Therefore, any analysis that computes returns starting from a specific point in time will be flawed. Thirdly, I think it's worth pointing out that diversification has value. An asset whose return is negatively correlated to the state of the world has some risk management benefits, which people may be willing to pay for, in excess of its "theoretical value".
Here is a pretty interesting database on the topic: http://www.bankofcanada.ca/wp-content/uploads/2015/05/crag-database-update-04-05-15.xlsx and a paper onn the same topic: https://journalistsresource.org/wp-...overeign-Defaults-and-Debt-Restructurings.pdf My general sense is that (a) Tyler Durden is right and (b) most of these defaults are not surprising.