@article{Vaupel_7_8, author = {Vaupel, James W.}, title={{Life Expectancy at Current Rates vs. Current Conditions: A Reflexion Stimulated by Bongaarts and Feeney’s "How Long Do We Live?"}}, journal = {Demographic Research}, volume = {7}, number = {8}, pages = {365--378}, doi = {10.4054/DemRes.2002.7.8}, year = {2002}, abstract = {Life expectancy is overestimated if mortality is declining and underestimated if mortality is increasing. This is the fundamental claim made by Bongaarts and Feeney (2002) in their article "How Long Do We Live?", where they base their claim on arguments about "tempo effects on mortality". This Reflexion explains why this claim is true in most heterogeneous populations. It suggests that demographers should be careful about distinguishing between life expectancy under current conditions, which is difficult and problematic to assess, and life expectancy at current rates, which can be estimated using standard methods. Finally, it speculates that there may be a deep connection between tempo and heterogeneity.}, URL = {https://www.demographic-research.org/volumes/vol7/8/}, eprint = {https://www.demographic-research.org/volumes/vol7/8/7-8.pdf} }