TY - JOUR A1 - Engelman, Michal A1 - Caswell, Hal A1 - Agree, Emily T1 - Why do lifespan variability trends for the young and old diverge? A perturbation analysis Y1 - 2014 DO - 10.4054/DemRes.2014.30.48 JF - Demographic Research VL - 30 IS - 48 SP - 1367 EP - -1396 ER -