We study the implications of patents in an overlapping generations model with horizontal innovation of differentiated physical capital. We show that within this demographic structure of finitely lived agents, weakening patent protection generates two contradicting effects on innovation and growth. Weakening patent protection lowers the (average) price of patented machines, thereby increasing machine utilization, output, aggregate saving, and investment. However, a higher demand for machines shifts investment away from the R&D activity aimed at inventing new machine varieties toward the formation of physical capital. The growth-maximizing level of patent protection is incomplete. Shortening patent length is more effective than loosening patent breadth in spurring growth, due to an additional positive effect on growth, that is decreasing investment in old patents. Welfare can be improved by weakening patent protection beyond the growth-maximizing level.

This paper discusses findings from a qualitative study which explored older adults' experiences of becoming regular exercisers in a gym triggered by health problems and their interactions with their younger gym instructors. A key question which the study sought to address was whether becoming embedded in the sub-field of exercise challenged traditional discourses of ageing (age habitus). While these older gym users reported significant benefits (greater health capital, expanded social networks and a return to active life after illness), they nevertheless were engaged in a complex and ambiguous negotiation of attitudes to bodily ageing and meanings of fitness and competence. In contrast, the instructors subscribed to a model of physical activity oriented towards physical capital as greater fitness. The paper suggests that these positions manifest competing understandings about what constitutes appropriate and desirable physical capital in later life. Budgetary constraints, beliefs about physical ability, professional expectations and the persistence of the discourse of decline prevent this gap from being easily bridged and allow alternative notions of ageing physicality to colonise the sub-field of exercise. The paper concludes that there is a need to develop ways of breaking down barriers in communication to overcome divergent understandings of what constitutes legitimate physical capital as we get older.