In your introduction, clearly state whether you agree or disagree with the proposed tax, for instance, 'I fundamentally disagree with the imposition of a higher tax on fast food.' Throughout your essay, maintain this stance by consistently presenting arguments that support your position. When acknowledging the opposing view, use concessionary language like 'While it is undeniable that fast food contributes to health issues,' immediately follow it with a strong counter-argument or a limitation of the tax's effectiveness to reinforce your main thesis.

When arguing against the tax, you could highlight its regressive nature, explaining how it disproportionately affects low-income households who often rely on affordable fast food options. Another strong point is the limited effectiveness of such taxes in fundamentally altering long-term dietary habits, as consumers might simply shift to other untaxed unhealthy alternatives. For example, studies on 'sugar taxes' in countries like Mexico have shown mixed results in sustained behavioural change, often leading to consumers switching to cheaper, equally unhealthy options.

The most common mistake on this question is to simply list the health problems associated with fast food and then conclude that a tax is a good idea without critically evaluating the mechanism and implications of such a tax. To avoid this, move beyond merely stating that fast food is unhealthy; instead, focus your analysis on whether a tax is the most effective, fair, and practical solution, considering its economic, social, and ethical dimensions.

To effectively transition between acknowledging the counter-argument and presenting your own, employ a 'concession-rebuttal' strategy. Start a paragraph by briefly conceding a point to the opposing side (e.g., 'Proponents of a fast food tax often argue that it could generate revenue for public health initiatives'). Immediately follow this with a strong transition and your counter-argument (e.g., 'However, this perspective often overlooks the regressive impact such a tax would have, disproportionately burdening lower-income families').

Examiners look for a nuanced and sophisticated argument that goes beyond a simplistic 'fast food is bad, so tax it' approach. A band 8-9 answer will demonstrate a deep understanding of the socio-economic implications of a tax, discussing concepts like regressive taxation, personal liberty, market distortions, and alternative policy solutions (e.g., education, subsidies for healthy food). The essay should present a well-developed line of reasoning, supported by relevant examples and precise academic vocabulary related to public policy and economics.