One application of capture-recapture, in addition to generating an estimate of population
size, is to evaluate the costs of ascertainment relative to the degree of accuracy obtained. A
primary goal of monitoring is to obtain accurate and timely incidence rates at a reasonable cost.
However, tradeoffs between costs and completeness are an implicit feature for many disease
monitoring systems. The more expensive it is to accurately estimate the counts of disease, the
less likely it is to assess that disease and the smaller the geographic coverage. For example, most
noncommunicable disease registries are willing to commit resources to achieve high rates of
ascertainment, whereas most passive surveillance systems sacrifice the accuracy of rates for
greater cost savings and broader coverage. With multiple sources in the monitoring system, the
cost-benefit analysis of the capture-recapture method will help us to identify the source
combination which provides reasonably good precision with a minimum of effort.