Elasticity analysis estimates the proportional change in the population growth rate for a proportional change in a vital rate (i.e. survival, growth or reproduction). It can be used to pinpoint those parts of an organism's life history that should be the focus of management effort, or those that contribute most to fitness. Recent theoretical work has emphasized some limitations of the technique, has overcome other problems, and has shown that it is robust to some violations of its underlying assumptions. Thus, although care is needed, elasticity analysis is a simple first step in answering important questions in evolutionary and population ecology.