The myth of the Budget poll bounce

In the run-up to a Budget there is usually plenty of speculation about whether the Budget will give the government a bounce, especially if tax cuts are in the air.

But do Budgets really move the polls?

Short answer: no.

Inspired by an old piece of analysis by Anthony Wells looking at Labour Budgets, I’ve done something similar for all the Budgets with a Conservative Chancellor from 2010 until last year. As with Anthony’s previous analysis, I’ve taken the two YouGov polls from before the Budget and the two YouGov polls from after the Budget to compare things.

Here’s what that analysis shows: an average boost in the Conservative vote share of… +0.1 points. That’s an average which mixes in falls and rises, but even the absolute average change is only 1.2 points. Only two of the 16 Budgets saw a change of 3 points or more.

UPDATE: View the latest data, including the March 2024 Budget, here.

Notes:

1. I have excluded YouGov polls with fieldwork on Budget day itself (20 in total in this period!). I think Anthony’s analysis included such polls and classified them as before/after depending when on the day the fieldwork stopped or started.
2. Why YouGov? (a) To inspire conspiracy theories, and (b) because there are a lot of YouGov polls and so the pairs of before/after polls are consistently close to the Budget.
3. There are various additional caveats and variations in the data, such as the Budget for which there is only one ‘before’ poll. I’ll include those if I tidy up and publish the data at some point but otherwise let me know if you have any queries.
4. The absence of an immediate bounce doesn’t mean that there aren’t longer term impacts on a party’s political standing. But the absence of such a bounce is still striking given how much coverage Budgets get and how much store politicians and pundits place on their impact.

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