I don't know if it's the strength of labor laws, per se, so much as the cost difference between different categories of employment. That can probably be quantif

I don't know if it's the strength of labor laws, per se, so much as the cost difference between different categories of employment. That can probably be quantified. It could be argued that today we have a Marxist-esque class conflict between the highly-paid and highly-privileged classes of the employed (usually permanent) and the low-paid and low-privileged classes (usually temporary or contractors). Limited to the wealthier countries of the first world, mind you. It does seem to work for the US and France, where a lot of benefits are tied to employment status. It falls apart for Germany, though.