IB Economics SL Internal Assessment Example

The student included two relevant externality diagrams with generally appropriate axes and labels, showing the right basic framework for the issue.

The diagrams communicate the intended distinction between the private equilibrium and the socially optimal outcome.

The deadweight-loss area is not accurately or clearly represented.

Figure 2 does not consistently match the explanation, so the relationship between the policy change and the curve shift is unclear.

The welfare loss created by the externality is only partly shown and not fully explained in the diagram itself.

The student uses a substantial range of relevant economic terminology, including MPB, MPC, MSB, MSC, market failure, overconsumption, and deadweight loss.

Most of the terminology is used in a way that makes the commentary understandable and economically grounded.

Some terms are not used precisely, especially when the student describes the vehicles as demerit goods without establishing information failure.

At points, the commentary blurs the distinction between weaker regulation, demand, and emissions, which weakens terminology accuracy.

The phrase 'supply shock' is not sufficiently justified in the context of the article.