Interesting article, I didn't know that "tragedy of the commons" was used to argue in favor of private ownership, rather I always thought it was used to demonstrate the need for some amount of regulations for things that cannot be meaningfully privatized (the quality of the air we breathe, the water we drink, the streets we use etc...). So pretty much the opposite of what the original author argued for apparently. It…
The argument can be used for both or either purpose. However, the modern popularizer of the term, ecologist Garret Hardin, lamented that the idea is widely misinterpreted. He claimed that he should have called it "the tragedy of the unregulated commons." I suppose if you just hear about the idea briefly during a single lecture of an intro econ course, it's easy to grasp the benefits of private ownership without recog…
Generally, the simpler these models are, the better, because complicating matters generally creates opportunities for bizzare arbitrage. By contrast, the proposed CO2 cap and trade (in the US) has so many well-intentioned loopholes with credits and the like that it will almost certainly cause unintended consequences like where an Indian manufacturer created and then sequestered a high-greenhouse-potential gas, resulting in a net emissions of CO2 (as well as a pointless use of resources).