Right-sizing observation systems: a biodiversity example using a cost-benefit approach

Although Earth observation systems are currently inadequate, hardly anyone can say what the optimum investment might be. An approach might be to size the system such that the marginal cost of a small incremental increase in effort is just more than the increase in net social benefit that results from the additional precision; and the savings from a marginal decrease in effort are less than the associated loss of social benefit. The approach is illustrated with an example based on wildlife survey in South Africa, made possible by a flourishing market for wildlife in the region, so the value per animal is reliably known, and the statistical benefit and incremental cost of increased observational effort are well understood. Results show that substantial increases in current survey efforts of high value animals are still possible before costs outweigh benefits. The study explores what this means for park managers and observation investment.