I didn't know about the Coase Theorem. The link between property right, transaction cost and externalities is not obvious and interesting.

We could imagine many tech examples similar to the school and highway :

- An ISP provides a connection with poor delay/jitter and it creates problem for software developers (Skype, multiplayer games,...) --> should the ISP compensate the developers or the developers pay the ISP to fix the problem?

- A developer is selling created a program that degrades the performance of another program if they are both run simultaneously. Who should pay who to compensate/fix the problem?