A multi-product cost function model was used to analyze energy demand in various agricultural subsectors. This approach has advantages over previously used approaches since it reduces aggregation bias, considers technological jointness, and provides various disaggregative measures related to energy input demand. When fitted to West Virginia county level data, labor and miscellaneous inputs in crop and livestock production were found to be substitutes for energy, while capital, machinery, and fertilizer were complementary to energy. Energy demand was inelastic and increases in machinery prices had the largest reduction effect on energy demand. Technological change was found to be capital, machinery, and fertilizer using, but it was labor and energy saving. Analyses indicated that the elasticity of demand for energy inputs with respect to livestock output was significantly larger than the elasticity with respect to crop output.

Taking four assumptions in turn, this review article considers some of the lenses through which researchers might look at later-life leisure travel and the implications of adopting each of them. First, we consider the ‘active ageing’ agenda and what this means for how leisure travel may be thought about in academia and beyond. Second, we turn to studies underpinned by worries about the appetite for significant consumption thought to typify the ‘baby-boomer’ generation and question whether these studies could inadvertently be promoting the very future they hope to avoid. Third, we explore how research on the benefits of everyday ‘mobility’ in later life may have morphed into a more general belief about the value of travel in older age. Finally, we reflect on how relevant studies of tourism are often underpinned by an argument about the financial rewards that now await those ready to target the older traveller. Our overall contention is that, though for different reasons, all four could be serving to encourage more later-life travel. Whilst for some this prospect is not at all troubling, the spectre of adverse energy demand consequences leads us to explore a more critical view.

The colossal squid (Mesonychoteuthis hamiltoni) is the world's largest invertebrate and its large size and some unique morphological characters have fuelled speculation that it is an aggressive top predator in the circum-Antarctic Southern Ocean. Here, we present estimates on the metabolic and energetic demands of this cold-water deep-sea giant. The estimated mass-specific routine metabolic rate for the colossal squid at 1.5°C was 0.036 µmol O2 h−1 g−1 and the projected daily energy consumption (45.1 kcal day−1) was almost constant as a function of depth in the nearly isothermal Antarctic waters. Our findings also indicate the squid shows a slow pace of life linked with very low prey requirements (only 0.03 kg of prey per day). We argue that the colossal squid is not a voracious predator capable of high-speed predator–prey interactions. It is, rather, an ambush or sit-and-float predator that uses the hooks on its arms and tentacles to ensnare prey that unwittingly approach.