Timothy B. Gage
Interests: Human biology, demography, population genetics, quantitative methods
I am interested in the evolution of life histories including the international, historic, pre-historic, and inter-ethnic variability of human demographic rates and the causes of this variability. I am currently pursuing research in several specific areas:
- Statistical modeling of infant mortality using population based parametric mixtures of logistic regression,
- Developing methods of demographic analysis applicable to endangered species, including the non-human primates, and
- Prehistoric human demography.
The ongoing research into infant mortality is developing statistical models for fully implementing the “proximate determinants model” of infant mortality. The models account for heterogeneity in the birth cohort using conventional parametric mixture models but extend the mixture model to include logistic probabilities of mortality on each mixture. The results to date suggest that heterogeneity may play a role in the well known “pediatric paradox”--that is, the observation that at low birthweight African-American mortality is lower than European-American mortality despite higher African-American infant mortality overall.
Director, Statistics and Computing for the Center for Social and Demographic Analysis
Jointly appointed with the Department of Epidemiology.
Select Publications Since 2000
Are Modern Environments Really Bad for Us?: Revisiting the Demographic and Epidemiologic Transitions. American Journal of Physical Anthropology, Suppl 41:96-117.
Gage, T.B. M.J. Bauer, N. Heffner, and H. Stratton. The pediatric paradox: Heterogeneity in the birth cohort. Human Biology, 76(3):327-342.
Eshed, V, Gopher, A. Gage, T.B. Hershkovitz, I. Has the transition to agriculture reshaped the demographic structure of prehistoric populations? American Journal of Physical Anthropology, 124:315-329.
Classification of births by birth weight and gestational age: An application of multivariate mixture models. Annals of Human Biology, 30(5):589-604.
The evolution of age and size at maturity. Human Biology, 75:521-537.
Modeling birthweight and gestational age distributions: Additive vs. multiplicative processes. American Journal of Human Biology, 14:1-7.
The age-specific fecundity of mammalian populations: A test of three mathematical models. Zoo Biology., 20:487-499.
Variability of gestational age distributions by sex and ethnicity: An analysis using mixture models. American Journal of Human Biology, 12(2):181-191.