IB Economics SL Internal Assessment Example

The student included a clearly relevant diagram that matches the policy context and shows the intended market intervention.

The diagram is titled and labelled, with axes and core market features identified.

The externality structure is not shown accurately, especially the relationship between MPB, MSB and the external cost.

Key welfare and tax-incidence features are unclear or misrepresented, which reduces the diagram’s economic accuracy.

Economic terminology is used consistently and is generally well integrated into the commentary.

Relevant concepts such as demerit good, negative externality, allocative inefficiency, indirect tax, government revenue and PED are applied in context rather than listed mechanically.

A few expressions are slightly too absolute, especially where tax burden and pass-through are described.

Some terminology would be more precise if it explicitly reflected elasticity and the shared incidence of indirect taxation.