<p><a>Parties make hundreds of campaign promises but not all are seen by
voters as central to a party's offering. Studies of government promise
fulfilment accept that not all promises are equivalent but in practice treat
all promises equally because they lack an appropriate means of measuring promise
centrality. To demonstrate the importance of accounting for pledge fulfilment,
we develop a conjoint experiment method to measure public opinion about promise
centrality which can be used to construct centrality weights. We demonstrate this
approach’s utility by examining the 2017 UK Conservative manifesto. Centrality
weighting reduces our assessment of Conservative promise-keeping by 21
percentage points (1.3 standard deviations of typical promise completion rates
found in comparative studies). Weighting increases the centrality of EU
promises sevenfold, immigration promises sixfold, and reduces the centrality of
miscellaneous administrative promises by more than half. These results
illustrate that pledge centrality cannot be ignored when assessing pledge
fulfillment.</a><i> </i></p>