Levin et al. deliver a sweeping lecture on the state of nature and society. They point out that economic and ecological systems are linked, this linkage is complex, and that in the litany of environmental disasters that awaits us ‘none can be treated by traditional markets, or regulatory policies.’ Markets fail because they do not aggregate information accurately; corrective policies fail too because lobbying efforts serve to polarize rather than galvanize public debate. Policymakers, social planners, and researchers are asked to rethink their typical conduct, and instead focus on the construction of flexible and adaptive institutions that can accommodate the uncertain future in a way that maintains human welfare. Trust and intellectual guidance are the ties that bind a better world to these undefined, but resilient new institutions.

Rates of time preference (RTPs) of rural households in Indonesia, Zambia and Ethiopia have been measured using hypothetical questions about preferences for current versus future consumption. In general, the rates were found to be very high. Factors influencing or correlated with the personal rates of time preference were investigated through regression methods. OLS was the technique used in the estimation. Market imperfections, particularly in credit and insurance markets lead to variation in RTPs. Poverty in assets, or cash liquidity constraints, was leading to or correlated with higher rates of time preference. The poor are, therefore, less likely to invest in environmental conservation. In Zambia, independent estimates of risk preferences were made. More risk-averse people tended to have lower RTPs. The results support the hypothesis that poverty and/or liquidity scarcity lead to high RTPs. Poverty reduction may thus reduce the RTPs of the poor and reduce the 'intertemporal externality' due to high RTPs. The high average RTPs indicate, however, that complementary policies may be needed to ensure sufficient levels of investment in conservation. Another logical implication is that institutionalization of private property rights may not be a sufficient tool to initiate sustainable resource management.

We, as a society, find ourselves confronted with a spectrum of potentially catastrophic and irreversible environmental problems, for which conventional approaches will not suffice in providing solutions. These problems are characterized, above all, by their unpredictability. This means that surprise is to be expected, and that sudden qualitative shifts in dynamics present serious problems for management. In general, it is difficult to detect strong signals of change early enough to motivate effective solutions, or even to develop scientific consensus on a time scale rapid enough to allow effective solution. Furthermore, such signals, even when detected, are likely to be displaced in space or sector from the source, so that the motivation for action is small. Conventional market mechanisms thus will be inadequate to address these challenges.

A contingent valuation method (CVM) survey to determine foreign and resident willingness to pay (WTP) for return visits to two different Costa Rican national parks was administered in 1995. WTP values were estimated for future entrance fees associated with proposed improvements to infrastructure and services in the Poas Volcano and the Manuel Antonio parks. Resulting logistic CVM models were statistically robust and mean WTP for entrance fees differed among the parks and were considerably higher than current fees. Results indicate that even in a developing country setting, the CVM is a useful tool to help determine park entrance fees in spite of the following methodological limitations which are recommended for further study: the need to include potential park visitors in survey samples; the lack of detailed information framing and contingent scenarios for park related WTP questions; and the threat of cultural-strategic biases when surveying residents of a developing country.

Levin et al. give us a sweeping vision of the notion of resilience and the response of management. In these comments I wish to discuss the daunting task of quantification of the resilience-based management issues raised by Levin et al. I also wish to suggest directions of future research.

I am in agreement with the main thesis of the paper by Levin et al., namely that complex, non-linear systems, whether ecological or socioeconomic, do not lend themselves to management protocols based on assumptions of linear, globally stable, single equilibrium systems. As the authors point out, policy makers need a better understanding of the concept of resilience. Furthermore, it is especially important for them to understand the crucial elements for maintaining resilience in the integrated ecological-socioeconomic resource use systems (the forests, rangelands, and agro-ecosystems) on which most human welfare depends.

Resilience is turning out to be a resilient concept. First proposed way back in the 1970s in the context of ecosystem dynamics, it was then dissected and elaborated–spawning terms such as malleability, elasticity, hysterisis, inertia, resistance, amplitude–as ecologists struggled to make it into something measurable, usable, and distinct from its notoriously slippery predecessor ‘stability’.

The modern study of stability in ecology can be said to have begun with the appearance of ‘Fluctuations of Animal Populations and a Measure of Community Stability’, by R.H. MacArthur in 1955. Since the publication of this influential paper, ecologists have investigated the properties of a number of different stability and stability-related concepts; the concepts of persistence, resilience, resistance, and variability readily come to mind. Of these various concepts, the concept of resilience itself appears to have been rather resilient. Indeed, as Neubert and Caswell (1997) and others have noted, today there is a vast literature on resilience. However, it is important to note that this literatur—to the best of my knowledge—has been primarily ecological in nature. In other words, the concept of resilience originated in ecology, and this concept has been applied and studied primarily in the context of ecosystems.