Job Market Paper

Managing Mortality of Multi-Use Megafauna

Aaron Enriquez & David Finnoff


Grizzly bears, which have recovered from the brink of extinction in the Greater Yellowstone Ecosystem, are a prime example of a multi-use species in that they induce both stock-dependent benefits and damages. Endangered Species Act (ESA) protections bar wildlife agencies from establishing active management to control the population. Instead, current management is reactive: agencies make management removals of conflict grizzly bears and humans occasionally kill grizzly bears in self-defense. This contributes to grizzly bears incurring high non-hunting mortality in spite of ESA protections. To shed light on an optimal recovery program, a bioeconomic model in the spirit of Rondeau (2001) is constructed and parameterized with available data. Results indicate the population has already surpassed the size at which ESA protections ought to have been removed and active management enacted. A key finding is that, along the recovery path, the natural capital value of a live grizzly bear may well be negative for an interval of time, during which it is optimal for society to continue to practice extreme conservation and develop a nuisance buffer of the species before switching to active management.

Yellowstone National Park, 2017

Working Papers

The Pain of Paying With Other People's Money
Aaron Enriquez, Ben Gilbert, and Linda Thunström


Spending decisions are at the heart of consumer research, and factors that impact spending have been studied for many decades. So far, research has focused on spending decisions based on own money. However, people often spend money earned by someone else (e.g., partners spend each other’s earned money, government officials spend tax payer money, employees spend employer money, people in need spend social benefits). We take a first step towards understanding how spending depends on who earned the money. We focus on the shortest social distance between consumer and earner - intra household spending - and survey 166 couples on how pain of paying from a fixed purchase is affected by who earned the money. Pain of paying regulates consumer spending; the higher the pain, the lower the spending. We find that people feel higher pain of paying when spending money earned by their partner, compared to when earned by self, suggesting they might be more frugal with money earned by others. Their pain of paying increases if they believe their partner will be unhappy with their purchases. Their ability to accurately predict the partner’s feelings about the purchase increases with partner similarity in spendthriftiness. 

In-Progress Research

Project: Nonmarket Valuation of Grizzly Bears

Researchers: Aaron Enriquez, Stephen Newbold, and David Finnoff


  • Use a combined stated and revealed preference nonmarket valuation survey to elicit how residents of Wyoming, Montana, and Idaho value grizzly bears in the Greater Yellowstone Ecosystem

  • Estimate and compare survey respondents' average willingness-to-pay to increase the probability of grizzly bear sightings from along the roads and from in the backcountry in Yellowstone and Grand Teton National Parks

  • Estimate respondents' average willingness-to-pay to increase the long-run persistence of the GYE grizzly bear population

  • Predict how hypothetical grizzly bear management policies could affect the aggregate demand for visits to Yellowstone and Grand Teton National Parks

Completed Work:

  • Obtained IRB approval for pretesting

  • Pretested the survey by running five focus groups and a one-on-one interview at the University of Wyoming

  • Secured funding for an expected sample size of 2,000 respondents

  • Obtained IRB approval for administering the online survey

  • Wrote a draft of the survey instrument

  • Conducted power analysis

Current Work:

  • Communicating with grizzly bear experts from three agencies to refine the survey instrument

  • Finalizing design of the choice sets

  • Aiming to administer the survey in May of 2020

Project: Nonmarket Valuation of Western Wind

Researchers: Aaron Enriquez & Robert Godby


  • Use a stated choice survey to determine what drives Wyoming residents' preferences for (or against) new wind energy developments

  • Elicit Wyoming residents' attitudes about competing energy sources (e.g., wind vs. coal)

Completed Work:

  • Obtained IRB approval for pretesting

  • Ran focus group sessions: three at the University of Wyoming and one at the Eppson Center for Seniors in Laramie, Wyoming

  • Secured funding for an expected sample size of 800 respondents

  • Obtained IRB approval for administering the online survey

Current Work:

  • Finalizing design of a pilot survey to further guide attribute selection for the choice experiment

  • Aiming to have the pilot survey administered in spring of 2020

Project: How Rural Parents Decide Whether to Vaccinate Their Children

Researchers: Alexander Marchal, Mariah Ehmke, Aaron Enriquez, and Carlos Camargo


  • Gain an understanding of what influences rural parents' decisions of whether or not to vaccinate their children

  • Observe whether parents' behavior in a voluntary contribution mechanism game mirrors their vaccination behavior

  • Determine how community and social network affect vaccination behavior

Completed Work:

  • Research team collected data from parents in four Wyoming communities

  • Analyzed results using a logit model

Current Work:

  • Writing draft


Economic Valuation of Grizzly Bears
Haub School of Environment and Natural Resources Student Research and Creative Activities Grant
PI: Aaron Enriquez
Co-authors: David Finnoff & Stephen Newbold
Amount: $1,000 for Spring 2019


  • Pretested a nonmarket valuation survey on peoples' willingness to pay for grizzly bears (in terms of both use and non-use values)

  • Ran five focus group sessions and a one-on-one interview with participants from the University of Wyoming in spring of 2019. Two sessions were for the general population, one session was for people who had been to Yellowstone or Grand Teton National Park in the past five years, one session was for people who had been hiking, backpacking, camping, or fishing anywhere in the past year, and one session was for people who had ever been big-game hunting anywhere

  • Used the knowledge gained to help inform attribute and level selection for the choice experiment

Other Relevant Research Experience

Small Scale Aquaculture as a Livelihood Alternative with Marine Conservation Benefits in Coastal Communities in Chile
Environment for Development Initiative Grant
PI: Jorge Dresdner
Co-authors: Carlos Chávez, Jo Albers, Aaron Enriquez, and Yanina Figueroa


  • Worked as a research assistant on the project

  • Facilitated writing the grant proposal

  • Obtained fieldwork experience by traveling to Southern Chile in April of 2018

  • Participated in stakeholder interviews (which were conducted in Spanish). Stakeholders included fisher organizations, government organizations, and artisanal fishers (e.g., shellfish divers, mussel farmers, seaweed collectors)

  • Ate amazing Chilean food!


UW-CSU Graduate Student Symposium
April 2019, Laramie, Wyoming

Presenter: "Bioeconomic grizzly bear management"

International Institute of Fisheries Economics & Trade
July 2018, Seattle, Washington

Presenter: "From the shore or from the water? Enforcement of resource rights under discrete enforcement technologies"

Abstract: Poaching is a major problem under the Chilean system of territorial use rights in fisheries (TURFs). Organizations of artisanal fishers that are granted spatial property rights through TURFs combat poaching by establishing their own enforcement. Although an organization must protect its benthic resources against poachers from both within the organization (“insiders”) and outside of the organization (“outsiders”), existing literature has shown that fishers are more concerned about enforcement against outsiders. Organizations know that their enforcement is imperfect - increasing enforcement increases the probability that poachers will be caught but does not guarantee that poachers will be caught. This probability depends on an “effectiveness of enforcement” parameter. With a high effectiveness of enforcement, an organization’s enforcement is more likely to lead to poacher capture. Using an optimal control framework, we analyze how a representative organization maximizes expected profit by choosing its levels of harvest and enforcement, over time. The organization incorporates the poacher’s best-response function, in which a poacher’s decision of how much to illegally harvest is influenced by the organization’s harvest and enforcement levels, the size of the stock, and exogenous parameters. In the case where the organization chooses positive levels of both harvest and enforcement, there are multiple equilibria in the steady state. One equilibrium is associated with a high level of stock while the other is associated with a low level. We show comparative dynamics on key parameters, including the effectiveness of enforcement.
Geological Society of America Annual Meeting
September 2016, Denver, Colorado

Presenter: "Economic feasibility of rare earth element extraction from Wyoming coal ash/char"

Abstract: The State of Wyoming is the largest producer of coal in the U.S. Uncertainty over the future of this resource has caused the state to recognize the importance of diversifying its mineral industry. Recent research shows a potential remedy: coal by-products, such as fly ash, can contain recoverable amounts of Rare Earth Elements (REEs). By producing REEs from fly ash, Wyoming can diversify and add to its revenue streams. There is global demand for REEs, as they are utilized in the production of a diverse array of modern goods and technology. Application of Net Present Value (NPV) analysis allows determination of the potential profitability of REE extraction from Wyoming coal-fired power station ash. The NPV analysis considers REE concentrations in six ash samples from two basins, the Powder River Basin and the Green River Basin. A challenge for NPV analysis of these samples is the lack of REE-from-coal-ash processing and refining cost estimates in the literature. To overcome this hurdle, the NPV analysis is structured to determine the maximum unit cost that a coal station can incur and still break even. For each station, this cost is calculated in two ways: as an input cost per pound of ash, and as an output cost per pound of Total Rare Earth Oxide (TREO). In addition to the unit cost, the analysis also provides the potential revenue and maximum capital cost for each station. Subsequent sensitivity analysis then allows for comparison of the results under scenarios that range from low to high yield and low to high REE concentrations. With the assumptions made, five of the six coal stations have breakeven unit costs that exceed the value of 1.17 US$ per pound TREO, which is the mine-to-oxide operating cost reported by the hard-rock mine company Molycorp. Under these results, REE recovery from Wyoming coal by-products appears economically promising.

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