Opposing Irreversibilities and Tipping Point Uncertainty
研究了经济不可逆性和环境临界点两种对立力量如何影响环境政策的最优时机与严格程度，通过生物入侵案例说明不同预防原则和不可逆性信念如何导致政策争论。
Irreversible environmental damage can lead to a more “conservationist” policy than would otherwise be optimal while sunk costs create an economic irreversibility that leads to policies that are less “conservationist” than they otherwise would be. The economic irreversibility effect is often larger than the effect of irreversible damage. We revisit this result with multiple uncertainties and a tipping point that triggers irreversible damage. An optimal stopping model over dynamic environmental lotteries is developed to characterize the optimal timing and stringency of an environmental policy subject to two kinds of irreversibility (economic and an environmental tipping point), two tipping point mechanisms (critical damage thresholds and random events), and two kinds of uncertainty (uncertain system dynamics and uncertainty in when the tipping point will be crossed). Using a bioinvasion example, results illustrate how differing definitions of precaution and beliefs about the degree of irreversibility may help explain persistent debates in environmental policy.