When is a “wait and see” approach to invasive species justified?

Predictions of damages and damages that might be avoided from invasive species control policies are marred by uncertainty that has both economic and ecological roots. Public policies directed at invasive species typically lag their detection. One possible explanation is the coupling of uncertainty with political and economic commitments creates an incentive to delay a policy response in order to gain more information on how damaging the invasion will be – a “wait and see” approach. We investigate whether this rationale is justified by identifying invasion characteristics that require the wait and see approach often adopted by lawmakers and government agencies. The model shows that the source of uncertainty and degree of policy irreversibility matter and allows the classification of invasive species with a low rate of spread and low levels of uncertainty as those where policies can be optimally timed in the future.