The short-run demand for jet fuel MRPsR is more inelastic than the long-run demand MRPLR. In the short run,airlines cannot reduce fuel consumption much when fuel prices increase. In the long run,however,they can take longer,more fuel-efficient routes and put more fuel-efficient planes into service. The short-run demand for jet fuel MRPSR is more inelastic than the long-run demand MRPLR. In the short run, airlines cannot reduce fuel consumption much when fuel prices increase. In the long run, however, they can take longer, more fuel-efficient routes and put more fuel-efficient planes into service