In this paper, we outline the three main concepts of 'ageism'; health maximisation ageism, productivity ageism, and fair innings ageism. We provide a methodological overview of the existing empirical literature on people's preferences regarding age and classify these studies according to the types of questions that have been asked. We consider some of the methodological issues involved in eliciting preferences regarding ageism and propose using a fixed duration of benefit rather than, as some studies have done, a benefit that lasts for a full lifetime. Informed by this discussion, we present the results from our own empirical study, carried out in the UK, which combines qualitative and quantitative methods to explore the reasons people have for choosing one age over another. In so doing, we are able to consider the extent to which respondents might bring extraneous factors to bear on their responses and/or disregard relevant information (such as that relating to the fixed nature of the benefit). The results suggest that people are broadly in favour of giving priority to younger over older people, based on arguments relating to both productivity ageism and fair innings ageism. However, respondents appear to assume that a benefit would last for a full lifetime (even if they are told to assume a fixed benefit), unless they are asked to consider a 'full-life' benefit first. This particular framing effect has important implications for preference elicitation studies, suggesting that if you want people to answer the question you have in mind, first ask them the question you think they may have in mind.