This paper, 1) outlines some of the challenges in obtaining participation from older sample members in a survey that is not specifically tailored to older people, 2) provides evidence of the relative response propensity of older people in such a survey and, 3) provides experimental evidence of potential influences on age-related response propensity. Specifically, we analyse differences between younger and older sample members in response propensity to each of a number  of components of the Understanding Society survey and we examine the interaction between respondent age and each of two experimentally-manipulated features of the Understanding Society Innovation Panel.