IB Economics SL Internal Assessment Example

The student included two relevant diagrams that were intended to support the externality and subsidy analysis.

The student made an effort to explain the diagrams in words rather than leaving them unexplained.

The main externality diagram contains a substantive accuracy error, so the market outcome is represented incorrectly.

The subsidy diagram is broadly relevant but not fully or accurately labelled, and the welfare effects are not clearly shown.

The student's written explanation of the first diagram conflicts with the graph and uses the wrong efficiency condition.

The student uses a good range of relevant economic terms such as market failure, subsidy, marginal social cost, consumer surplus, producer surplus, and sustainability.

The student's vocabulary generally shows awareness of the subject-specific language expected in an economics commentary.

Several key terms are used imprecisely, especially when describing emissions as a negative externality of production rather than of vehicle use.

Some terminology is applied inconsistently with the diagrams and argument, which weakens credibility.

Important efficiency language is misstated, especially the condition for the socially optimal outcome.