|dc.description.abstract||In their respective memoirs, mountaineers David Roberts and Ed Viesturs express a fundamental
disagreement over the risks associated with climbing high-altitude (8000m) peaks.
(Viesturs and Roberts, 2006, Roberts, 2005). For Roberts, the risk of dying on an expedition
to an 8000m peak is effectively static, and so he likens it to Russian roulette. (Viesturs
and Roberts, 2006, 308) Based on a 1997 study showing that “on any given expedition to
an [8000m] peak. . . a climber stands a 1-in-34 chance of dying,” Roberts calculates that
Viesturs had cumulatively faced a 60 percent chance of dying over his thirty expeditions
on 8000m peaks.1 (Roberts, 2005, 348-49)...
This study sheds some statistical light on the Roberts-Viesturs debate and assesses
whether experience is associated with lower fatality risk on 8000m peaks. Using a comprehensive
dataset of high-altitude climbing expeditions in the Nepalese Himalaya, the
study will estimate the conditional death risk for a member of an 8000m expedition given
that climber’s number of previous expeditions. Conditional death risks are after all the
core of the Roberts-Viesturs controversy. Roberts contends that the risk is constant (unconditional);
Viesturs suggests that the risk of death should decrease with each ensuing
Finally, I augment these basic results with three supplemental analyses. First, I offer
some power calculations to justify the TTT method. Second, to control for possible
confounding factors, such as year and mountain, I use a discrete-time survival analysis to
model baseline hazard probabilities, which are then tested for constant or decreasing rates.
Finally, to provide a useful juxtaposition, I examine the probability of ascent on 8000m
peaks, asking whether previous 8000m experience increases the probability of reaching