IB Economics SL Internal Assessment Example

The student included two relevant, clearly titled diagrams that support the policy argument.

The diagrams are broadly accurate and correctly labelled, including the welfare-loss area and the $0.20 per litre tax.

The visual distinction between private and social outcomes helps make the externality argument clear.

The tax diagram is not fully secure conceptually because the labels and explanation are not entirely consistent about the cost curves.

The explanation of the tax shift contains an economic inaccuracy, which weakens the reliability of the diagram discussion.

The diagrams would be stronger with a clearer distinction between consumer price, producer price, and the tax wedge.

A strong range of relevant economic terms is used, including negative externality, demerit good, indirect tax, welfare loss, and tax revenue.

Most terminology is linked to the article’s policy debate rather than being used in isolation.

Key terms are often used meaningfully enough to show a sound grasp of the topic overall.

Some important terms are used imprecisely, especially around the tax shift and the nature of the externality.

The commentary sometimes blurs the difference between a consumption externality and a production-cost problem.

A few definitions are reversed or not fully accurate, which reduces consistency.