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The effective management of fish populations requires understanding of both the biology of the species being managed and the behavior of the humans who harvest those species. For many marine fisheries, recreational harvests represent a significant portion of the total fishing mortality. For such fisheries, therefore, a model that captures the dynamics of angler choices and the fish population would be a valuable tool for fisheries management. In this study, we provide such a model, focusing on red drum and spotted seatrout, which are the two of the main recreational fishing targets in the Gulf of Mexico. The biological models are in the form of vector autoregressive models. The anglers' decision model takes the discrete choice approach, in which anglers first decide whether to go fishing and then determine the location to fish based on the distance and expected catch of two species of fish if they decide to go fishing. The coupled model predicts that, under the level of fluctuation in the abundance of the two species experienced in the past 35 years, the number of trips that might be taken by anglers fluctuates moderately. This fluctuation is magnified as the cost of travel decreases because the anglers can travel long distance to seek better fishing conditions. On the other hand, as the cost of travel increases, their preference to fish in nearby areas increases regardless of the expected catch in other locations and variation in the trips taken declines. The model demonstrates the importance of incorporating anglers' decision processes in understanding the changes in a fishing effort level. Although the model in this study still has a room for further improvement, it can be used for more effective management of fish and potentially other populations.

Uncertainties inherent in fisheries motivate a precautionary approach to management, meaning an approach specifically intended to avoid bad outcomes. Stochastic dynamic optimization models, which have been in the fisheries literature for decades, provide a framework for decision making when uncertain outcomes have known probabilities. However, most such models incorporate population dynamics models for which the parameters are assumed known. In this paper, we apply a robust optimization approach to capture a form of uncertainty nearly universal in fisheries, uncertainty regarding the values of model parameters. Our approach, developed by Nilim and El Ghaoui (Oper Res 53(5):780–798, 2005), establishes bounds on parameter values based on the available data and the degree of precaution that the decision maker chooses. To demonstrate the applicability of the method to fisheries management problems, we use a simple example, the Skeena River sockeye salmon fishery. We show that robust optimization offers a structured and computationally tractable approach to formulating precautionary harvest policies. Moreover, as better information about the resource becomes available, less conservative management is possible without reducing the level of precaution.

Does environmental quality affect firms’ activities that might improve that quality? In this paper, we use China's public heating policy as a quasi-experiment to investigate the impact of exogenous pollution differences on green innovation behavior. We use a regression discontinuity model, and carry out a suite of robustness tests. We consistently find that firms located in cities with an exogenous source of heavy pollution tend to adopt green innovation at a lower rate while we find no difference in the rate at which they adopt non-green innovation. We find a strong causal effect: being north of the boundary, where pollution levels are higher, leads firms to adopt less green innovation. Firms located in the heating areas report roughly 1 less green innovation per billion RMB of assets, a substantial difference given the average number of green innovations per billion RMB of assets of northern firms is 0.641.

The concerns about the contradiction between agricultural production and Agricultural Non-Point (ANPS) pollution has become increased with economic development in China. Government interventions are key to controlling ANPS pollution through the establishment of laws and policies. This paper uses the entropy method to calculate the emissions amount of ANPS pollution and policy strength of 31 provinces from 2010 to 2019 in China. The dynamic panel data model with system generalized moment is used to estimate the impacts of policies with different measures on ANPS pollution emission. According to our findings, China's policies have been helpful in controlling ANPS pollution though there are important regional differences. Moreover, four types of policy measures all contribute to the reduction in ANPS pollution. These findings improve our understanding of the relationship between policies and ANPS pollution in the analyzed period, thus providing support for the formulation of pollution management strategies in the next stage.

We investigate the unintended consequences of carryout grocery bag (CGB) regulations by looking at the impact on sales of alternative plastic bag products. We extend the literature by studying two types of CGB regulations, bag bans and bag fees. Using retail scanner data and employing a general synthetic control method, we find that both types of CGB regulations are associated with significantly higher plastic trash bag sales. We estimate that CGB regulations lead to an average increase in purchased plastics of 127 pounds per store per month, ranging from 30 to 135 (37–224) pounds for 4-gallon (8-gallon) trash bags. These results confirm previous findings on bag bans and provide new evidence on bag fees. In general, the effects do not differ across CGB regulations, but some heterogeneity exists. Our results highlight unintentional spillover effects of narrowly targeted policies on other unregulated waste.

We use propensity score matching to estimate additionality from enrollment in federal cost-share programs for six practices. We analyze farmer adoption decisions based on farmer survey data in Ohio. We develop a new methodological approach to decompose the average treatment effect on the treated according to relative contributions of voluntary adopters and new adopters. Our results indicate that cost-share programs achieve positive levels of additionality for each practice. But percent additionality varies dramatically between practices. Specifically, percent additionality is highest for hayfield establishment (93.3%), cover crops (90.6%), and filter strips (88.9%), while it is lowest for conservation tillage (19.3%).

It is difficult to control agricultural Non-point Source (NPS) pollution, caused by overusing of chemical fertilizer, through laws alone. An agricultural extension program is an alternative way to reduce fertilizer input. This paper estimates the average change in fertilizer use of farmers, which is attributable to their participation in the agricultural extension program. The Inverse-Probability Weighted matching method is used to evaluate the average treatment effect for the farmers who engaged in the program and, to a limited extent, evaluate the impact of individual elements of the program. Surprisingly, we find that farmer-to-farmer training may have had a counterproductive effect while the posters may be the most effective program element in reducing fertilizer use in the context.

Most efforts to establish precautionary guidelines for fisheries management use essentially ad hoc impressions as to what constitutes conservative management. Such approaches, however, fail to take into account the magnitude of the uncertainty about particular systems. One alternative approach to precautionary management is robust control, in which decision makers attempt to maximize an outcome under the assumption that the conditions will be worse than expected. In this paper, we apply a robust optimization approach to estimate the maximum sustainable yield and other reference points for the Chesapeake Bay blue crab Callinectes sapidus fishery. This approach is relatively easy to implement in standard stock assessment models that use a maximum‐likelihood approach to estimate model parameters. In addition, it has the advantage that a standard level of precaution can be chosen by decision makers and then applied to different fisheries with vastly different levels of data and analysis.

Environmental economists have traditionally addressed the issue of choice under uncertainty by applying the expected utility hypothesis. When policymakers face a panel of experts with widely divergent beliefs, the problem may more accurately be described as a case of choice under pure uncertainty. Arrow and Hurwicz (1972) demonstrate that rational choice criteria under pure uncertainty will focus on the extremes of the state space, not the midpoint as is typically assumed. Using Nordhaus's DICE model, uncertainty-based choices about global warming policies are evaluated. Linkages to the safe minimum standard and the precautionary principle are also discussed.

Lack of adoption of soil health–promoting practices (SHPPs) leaves soil vulnerable to erosion, exacerbating flooding and contributing to high nutrient and sediment levels in surface waters. To aid in the adoption of SHPPs, changes in soil health need to be measured and related to things that both clearly and directly matter to farmers and stakeholders, yet soil scientists still grapple with which indicators to measure when assessing soil health. Useful indicators of soil health show changes in soil function resulting from changes in soil management, are measurable, and have clear and direct value to their target audience. These “linking indicators” need to be identified in context for successful promotion of SHPPs. We collected data from two focus groups of farmers in the Brazos River Watershed, TX, who had either adopted SHPPs or who had not. Content analysis of focus group transcripts revealed soil health was an important part of a farmer's stewardship ethic. Farmers perceived that water management, organic matter, yield, and biomass were meaningful indicators of soil health that benefited their enterprise. However, using yield and biomass alone has the potential to create a “false positive” for soil health. When farmers chose their management practices, two themes interacted with farmer concerns for soil health: profitability and social interactions. This work provides context and recommended linking indicators for soil scientists to use for communication with farmers. Researchers and policymakers should be aware of these interactions if efforts to promote SHPP adoption are to be successful.