What is market failure? Market failure is defined as the situation where the free market fails to achieve allocative efficiency – the market fails to achieve an outcome that maximizes society’s welfare. Government intervention during market failure may in certain cases be justified, but in other cases unjustified. This essay intends to discuss if government intervention in markets that fail is justified and effective, by addressing and focusing on the economic problem of externalities, demerit goods, and the lack of provision of public goods. Governments can utilise various methods to address externalities and demerit goods. Externalities are third party spillover effects, and can be both positive and negative, and can come from consumption or production sides. Demerit goods are goods that either cause negative externalities, or are goods that governments deem unacceptable for their citizens, for instance smoking and gambling. In the case of negative externalities and demerit goods, when goods are over-consumed as their marginal social costs exceed the marginal social benefit, the government may adapt the use of an output tax to prevent the over-consumption of the good.
[Insert a diagram on output tax showing how this policy cures the problem] Imposing a tax per unit that is equal to the MEC shifts the MPC to the left. The new private equilibrium now coincides with the new social equilibrium Qs where MSB = MSC. Allocative efficiency is achieved as the output has been reduced to the social optimal level and therefore government intervention is justified. Alternatively, the government may also impose an output quota which is defined as the limit for the quantity that the industry can legally produce, therefore effectively reducing the over-consumption of the good generating either negative externalities or demerit