Sometimes regulations help businesses by limiting the ability of firms to engage in activities that bring them greater profits in the short run but ultimately destroy the common resource that all business firms need. For example, regulating the intensity of fish farming may reduce the profits of individual fish farms but help the fish-farming industry as a whole by preserving the quality of water that all the fish farms have to use. For another example, it may be in the interest of individual firms to employ children and lower their wage bills. However, a widespread use of child labour will lower the quality of the labour force in the longer run by stunting the physical and mental development of children. [...]