Browsing by Author "Wu, Shang"
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Item Auction versus Posted Price in Experiments: Comparisons of Mean and Marginal Effect(Department of Applied Economics and Statistics, University of Delaware, Newark, DE., 2017-06) Wu, Shang; Fooks, Jacob; Li, Tongzhe; Messer, Kent D.; Delaney, DeborahEconomic experiments have been widely used to elicit individuals’ evaluation for various commodities and non-market goods. Common elicitation methods include auctions and posted price mechanisms. Experimental auctions are theoretically incentive compatible so are assumed to give an unbiased estimate of individuals’ evaluation including willingness to pay (WTP). However, the vast majority of purchasing decisions are not made in auctions but in market settings, such as grocery stores, where consumers make yes/no decisions in response to a set price. In this research, we carefully design an experiment to compare homegrown-value WTP estimates between an auction and a posted price elicitation format. This design enables us to make both within- and between-subjects comparisons of the mean WTP and marginal effect estimates. Results from 115 adult consumers indicate that WTP estimates obtained from an auction are approximately 32% - 39% smaller than WTP estimates obtained from a posted price mechanism. In addition, we compare the statistical significance and conclude that auctions require a smaller sample size than posted price mechanisms in order to detect the same preference change. Nevertheless, the signs of marginal effects for different product characteristics are consistent in both mechanisms.Item Consumer Demand for Local Honey: An Artefactual Field Experiment(Department of Applied Economics and Statistics, University of Delaware, Newark, DE., 2014-05) Wu, Shang; Fooks, Jacob; Messer, Kent D.; Delaney, DeborahHow to best target and attract niche market consumers is an important marketing problem for producers of specialty agricultural products. It is particularly an issue in the honey market where consumers increasingly face media messages regarding threats to honey bee health, honey adulteration, and health benefits of locally produced honey. Using auction experiments, this research evaluates consumer behavior related to informational messages about honey that is produced locally, domestically, and internationally. Results from 115 adult consumers show that consumers’ demand for honey varies significantly based on the geographic location of the honey’s production, product packaging, and the information they have about the product. Consumers demonstrate greater demand for locally produced honey, especially when provided information about negative aspects of internationally produced honey that include adulteration. This shows that such negative media attention on specialty products offers small producers an opportunity to increase profitability by marketing themselves as a specialized niche alternative.Item Do auctions lower WTP estimates? An artefactual field experiment(University of Delaware, 2013) Wu, ShangThis study compares the willingness to pay (WTP) estimates for a jar of honey from a second price Vickrey auction to the Posted Price setting (also known as the dichotomous choice, or the take-it-or-leave-it) with 115 adult participants. Consumers‘ WTP are about 50% lower in the auction compared to the Posted Price. Several potential explanations are proposed for the difference.Item Do Auctions Underestimate Consumer WTP? An Artefactual Field Experiment(Department of Applied Economics and Statistics, University of Delaware, Newark, DE., 2014-05) Wu, Shang; Fooks, Jacob; Messer, Kent D.; Delaney, DeborahAuction experiments are commonly used to elicit consumer values for a wide range of items and services. These auctions are theoretically incentive compatible so are assumed to give an unbiased estimate of consumers’ willingness to pay (WTP). However, the vast majority of consumer decisions are made not in auctions but in posted-price settings, such as grocery stores. This study tests whether the two mechanisms yield similar WTP estimates by comparing WTP for honey from a second-price Vickrey auction and the WTP from a posted-price dichotomous-choice mechanism in a within-subject, homegrown-value setting. Results from 115 adult consumers indicate that estimates of WTP generated by an auction are approximately 50% smaller than WTP estimates generated by a posted-price mechanism. We test several potential explanations for this difference in behavior and find no evidence of anchoring or yea-saying effects. The evidence does suggest that the framing of choice in an auction format and a lack of familiarity with auctions are the most plausible explanation for this downward bias.Item Essays on experiments and agent-based modeling(University of Delaware, 2017) Wu, Shang[CHAPTER 1] Heterogeneous agents and information nudges in non-point source water pollution management: Non-point source (NPS) water pollution from agricultural runoff is a leading cause of impairment for many water bodies in the United States; however, sources of NPS pollution are difficult to identify because of hidden actions and asymmetric information. Theoretical and experimental research has shown that ambient pollution policies can induce groups to reduce pollution to socially efficient levels, but many of these studies have imposed restrictive assumptions about farmer homogeneity and management choices. In reality, agricultural firms differ in both size and location, and farmers make numerous management decisions that can affect runoff and nutrient loss, including decisions about production intensity and pollution abatement technologies. Researchers have shown that introducing either size or location heterogeneity affects the efficiency of ambient pollution policies, but no research has analyzed policy performance while considering several sources of heterogeneity and multiple management decisions. Furthermore, despite multiple examples in using non-pecuniary interventions to promote environmental conservation, little research has examined how to use information nudges, like social comparisons or information about peer actions, to induce better NPS pollution abatement decisions. ☐ In this study, we designed an economic experiment to test the effects of multiple layers of heterogeneity, information nudges, and an extended decision space on the performance of the classic ambient tax/subsidy policy. Experiment participants (n=192) were recruited from a large public university in the U.S. In the experiment, each individual was assigned a firm and asked to make individual decisions that affected the profitability of his/her firm and ambient water pollution of their group. In each round of the experiment, participants selected their production intensity and chose one of two production technologies—a conventional technology or a more expensive technology that generated less pollution. ☐ Eight within-subject treatments were tested, including two policy variations (no policy and a tax/subsidy policy) and four size/location variations (homogeneous, location heterogeneity, size heterogeneity, and both location and size heterogeneity). Three between-subject information treatments were also tested, including a no information control. In information treatment 1, we tested how individual decisions were affected by information nudges about decisions that similar individuals had made in past sessions. In information treatment 2, participants were provided with information about the average production and technology adoption rate in their group during the last round. A unique dominant strategy Nash Equilibrium was calculated for both the adoption decision and production decision based on location and size. ☐ Our results demonstrate that, without information nudges, more firm heterogeneity reduces the effectiveness of ambient tax/subsidy policies and target pollution levels are achieved less frequently. However, the tax/subsidy policy was effective under different heterogeneity scenarios when information is provided about peer and group decisions in past rounds. Furthermore, information treatment 1 and information treatment 2 generate higher policy efficiency than no information treatment. Lastly, participants are able to find and retain their dominant strategy better in the information 1 treatment, suggesting that providing individually targeted information is more effective than providing information about aggregate group-level decisions. Our findings suggest that traditional ambient pollution policies may be less effective when agents are heterogeneous and make multiple decisions that affect pollution, but information nudges can improve policy performance. ----- [CHAPTER 2] Simulating Heterogeneous Farmer Behaviors under Different Policy Schemes: Integrating Economic Experiments and Agent-Based Modeling: In this paper, we develop an agent-based model that scales up results from economic experiments on technology diffusion and abatement of non-point source water pollution under the conditions of an actual watershed. The results from the economic experiments provide the foundation for assumptions used in the agent-based model. Data from geographic information systems and the US Census of Agriculture initialize and parameterize the model. This integrated model enables the exploration of the effects of several policy interventions on technology diffusion and agricultural production and, hence, on agricultural non-point source pollution. Simulation results demonstrate that information ‘nudges’ based on social comparisons increase ambient based policy performance as well as efficiency, especially individual-level tailored information on what others like them have done in past similar situations. ----- [CHAPTER 3] Auctions versus Posted Price in Experiments: Comparisons of Mean and Marginal Effect: Economic experiments have been widely used to elicit individuals’ evaluation for various commodities and non-market goods. Common elicitation methods include auctions and posted price mechanisms. Experimental auctions are theoretically incentive compatible so are assumed to give an unbiased estimate of individuals’ evaluation including willingness to pay (WTP). However, the vast majority of purchasing decisions are not made in auctions but in market settings, such as grocery stores, where consumers make yes/no decisions in response to a set price. In this research, we carefully design an experiment to compare homegrown-value WTP estimates between an auction and a posted price elicitation format. This design enables us to make both within- and between-subjects comparisons of the mean WTP and marginal effect estimates. Results from 115 adult consumers indicate that WTP estimates obtained from an auction are approximately 32% - 39% smaller than WTP estimates obtained from a posted price mechanism. In addition, we compare the statistical significance and conclude that auctions require a smaller sample size than posted price mechanisms in order to detect the same preference change. Nevertheless, the signs of marginal effects for different product characteristics are consistent in both mechanisms.Item Heterogeneous Agents and Information Nudges in Non-Point Source Water Pollution Management(Department of Applied Economics and Statistics, University of Delaware, Newark, DE., 2017-06) Wu, Shang; Palm-Forster, Leah; Messer, Kent D.Non-point source (NPS) water pollution from agricultural runoff is a leading cause of impairment for many water bodies in the United States; however, sources of NPS pollution are difficult to identify because of hidden actions and asymmetric information. Theoretical and experimental research has shown that ambient pollution policies can induce groups to reduce pollution to socially efficient levels, but many of these studies have imposed restrictive assumptions about farmer homogeneity and management choices. In reality, agricultural firms differ in both size and location, and farmers make numerous management decisions that can affect runoff and nutrient loss, including decisions about production intensity and pollution abatement technologies. Researchers have shown that introducing either size or location heterogeneity affects the efficiency of ambient pollution policies, but no research has analyzed policy performance while considering several sources of heterogeneity and multiple management decisions. Furthermore, despite multiple examples in using non-pecuniary incentives to promote environmental conservation, little research has examined how to use information nudges, like social comparisons or information about peer actions, to induce better NPS pollution abatement decisions. In this study, we designed an economic experiment to test the effects of multiple layers of heterogeneity, information nudges, and an extended decision space on the performance of the classic ambient tax/subsidy policy. Experiment participants (n=192) were recruited from a large public university in the U.S. In the experiment, each individual was assigned a firm and asked to make individual decisions that affected the profitability of his/her firm and ambient water pollution of their group. In each round of the experiment, participants selected their production intensity and chose one of two 2 production technologies—a conventional technology or a more expensive technology that generated less pollution. Eight within-subject treatments were tested, including two policy variations (no policy and a tax/subsidy policy) and four size/location variations (homogeneous, location heterogeneity, size heterogeneity, and both location and size heterogeneity). Three between-subject information treatments were also tested, including a no information control. In information treatment 1, we tested how individual decisions were affected by information nudges about decisions that similar individuals had made in past sessions. In information treatment 2, participants were provided with information about the average production and technology adoption rate in their group during the last round. A unique dominant strategy Nash Equilibrium was calculated for both the adoption decision and production decision based on location and size. Our results demonstrate that, without information nudges, more firm heterogeneity reduces the effectiveness of ambient tax/subsidy policies and target pollution levels are achieved less frequently. However, the tax/subsidy policy was effective under different heterogeneity scenarios when information is provided about peer and group decisions in past rounds. Furthermore, information treatment 1 and information treatment 2 generate higher policy efficiency than no information treatment. Lastly, participants are able to find and retain their dominant strategy better in the information 1 treatment, suggesting that providing individually targeted information is more effective than providing information about aggregate group-level decisions. Our findings suggest that traditional ambient pollution policies may be less effective when agents are heterogeneous and make multiple decisions that affect pollution, but information nudges can improve policy performance.Item Simulating Heterogeneous Farmer Behaviors under Different Policy Schemes: Integrating Economic Experiments and Agent-Based Modeling(Department of Applied Economics and Statistics, University of Delaware, Newark, DE., 2017-06) Wu, Shang; Zia, Asim; Ren, Mengyuan; Messer, Kent D.In this paper, we develop an agent-based model that scales up results from economic experiments on technology diffusion and abatement of non-point source water pollution under the conditions of an actual watershed. The results from the economic experiments provide the foundation for assumptions used in the agent-based model. Data from geographic information systems and the US Census of Agriculture initialize and parameterize the model. This integrated model enables the exploration of the effects of several policy interventions on technology diffusion and agricultural production and, hence, on agricultural non-point source pollution. Simulation results demonstrate that information ‘nudges’ based on social comparisons increase ambient based policy performance as well as efficiency, especially individual-level tailored information on what others like them have done in past similar situations.