The most dangerous flight I ever took was in a ten seater plane going to the smallest of Ireland’s Aran Islands. The danger was not so much the size of the plane as landing on Inis Meain, the last of the three islands, so there were five take-off and landing events to survive.
According to a new measure of risk proposed by Luca Anderlini and Leonardo Felli on the website Vox EU, that trip had an SVI of three. The Systemic Vulnerability Index they suggest would measure the risk of an indirect security in extreme market conditions by assuming additional risk is added with every layer. Thus if you buy a German government bond yourself, that has an SVI of 1. If you commission a bank to buy it and sell you a mirror image contract, that has an SVI of 2. A CDO squared could have an SVI of 3 or 4.