IB World Studies SL Extended Essay Example

The title is specific, localised, and clearly linked to the investigation’s purpose. By naming Ohio’s intervention and the outcome of vaccine uptake, the student establishes a focused case study rather than a vague topic.

This question is clearly framed as an evaluative inquiry and it signals a bounded policy, place, and intended effect. That makes the essay manageable and helps the reader understand what evidence should be brought forward.

This broadens the investigation away from the core research question and weakens focus. The student should either justify why labour supply and output are necessary to answer a question about hesitancy, or remove this line of inquiry so the analysis stays tightly aligned to the stated aim.

The student should tighten the operational definition here by explaining why first-dose uptake is the best proxy for hesitancy and what its limitations are. As written, the method is plausible, but the link between hesitancy and uptake needs to be made more explicit and consistently used throughout the essay.

The student shows strong disciplinary awareness by connecting vaccination to merit goods and positive externalities. This works well because it immediately frames the policy as a market-failure issue rather than just a descriptive health intervention.

This is conceptually inaccurate: $MSC$ is being misnamed, and reaching the social optimum does not mean hesitancy is “ruled out.” The student should correct the terminology and distinguish between an efficient vaccination level and the complete disappearance of hesitant beliefs.

The economic logic is good here, but the student should be careful not to treat the diagram as proof of the policy outcome. This section explains why intervention may be justified; it does not yet demonstrate that the lottery actually moved Ohio toward the social optimum.

The phrase “large cash prices” is inaccurate, and the argument would be stronger if the student distinguished between salience as a theoretical mechanism and the actual empirical effect of the lottery. The current wording overstates how directly the theory supports the policy result.

The student could strengthen this by showing more clearly how a low-probability lottery reward would be processed through deliberative decision-making rather than assuming System 2 automatically supports the incentive. A brief link to expected value or bounded rationality would make the psychological application more convincing.

This interpretation is reversed. Ohio’s rate is lower than synthetic Ohio’s, so the difference indicates a shortfall, not an increase. The student must correct the direction of the result because this error undermines the reliability of the later conclusion.

The student should distinguish between statistical significance and practical effect more carefully. The wording is also grammatically and analytically imprecise; a stronger version would state that the study found no statistically significant increase in Ohio’s vaccination share relative to the synthetic control.

This is a clear, evidence-led conclusion that follows from the main empirical source. The student does well to bring the essay back to the research question and avoid overstating the policy’s success.

The student should revise this sentence to avoid ambiguity and to reflect the actual direction of the comparison. A concise correction would improve the analytical precision and make the final argument more credible.

What evidence from the Ohio study specifically supports the claim that the lottery worked only for weakly hesitant individuals? If that evidence is not direct, the student should qualify this statement more carefully or present it as a hypothesis rather than a conclusion.

The report follows a clear academic structure, and the table of contents shows that the reader is being guided through a planned sequence of sections. This helps readability and signals an organised investigation.

This introduction clearly situates the local case within a wider global issue, which is exactly what a World Studies investigation needs. The reader is told both what is being studied and why it matters beyond Ohio.

This section is structurally well signposted, but it is disproportionately large relative to its relevance to the research question. The student should streamline this part or justify it more directly, so the report’s structure better matches the actual inquiry.