Grantee Research Project Results
2004 Progress Report: Valuing Reduced Asthma Morbidity in Children
EPA Grant Number: R829665Title: Valuing Reduced Asthma Morbidity in Children
Investigators: Hanemann, Michael
Current Investigators: Hanemann, Michael , Brandt, Sylvia
Institution: University of California - Berkeley , University of Massachusetts - Amherst
EPA Project Officer: Hahn, Intaek
Project Period: May 14, 2002 through December 31, 2006
Project Period Covered by this Report: May 14, 2004 through December 31, 2005
Project Amount: $328,205
RFA: Valuation of Environmental Impacts on Children's Health (2001) RFA Text | Recipients Lists
Research Category: Human Health , Children's Health , Environmental Justice
Objective:
The objective of this research project is to reexamine the phenomenon of embedding in stated preference (SP) surveys with the aim of identifying the circumstances that are conducive to the occurrence of this phenomenon and investigating whether there are ways of structuring an SP survey such that embedding can be controlled or eliminated. The approach adopted here involves: (1) forming an understanding of the reasons why embedding may be occurring; (2) identifying ways of testing these explanations for embedding; (3) identifying some suitable SP surveys that have appeared in the literature and have exhibited signs of embedding; and (4) replicating these studies with appropriate modifications to test the explanations for embedding that might control for it as identified in item (2).
Progress Summary:
The work conducted during this period dealt mainly with item (4). A suite of three surveys was designed and implemented that replicated several studies on embedding to be found in the existing literature. The studies are as follows:
Study A. This study was designed to replicate Boyle, et al. (1994), which deals with scope effects and possible insensitivity to scope. The hypothesis is that the insensitivity found in the original study reflects the fact that individuals focus on relative (proportional) effects rather than absolute effects. There is evidence in the psychological literature to support the hypothesis but not in the economic literature; hence, the usefulness of this study. The method was to replicate the circumstances of data collection using the same survey instrument and the same survey locations but modifying the instrument to frame the impact in terms of the percentage of the bird population affected. The study involved an intercept survey in Southlake and Lakeshore shopping malls in the Atlanta metropolitan area. Recruited participants were people over the age of 19 but not full-time students. There were no incentive payments for participants, but participants were offered coffee or tea and cookies.
Study B. The study was designed to replicate Payne, et al. (2000), which asked people to value five different environmental programs. It was a split sample in which everybody valued the same items, but the order in which the items were presented and valued varied among subjects. In consequence, strong embedding and order effects were observed, whereby the valuation of an item depended on the order in which it was presented. In the replication, the sequential method used by Payne, et al. (2000), is paired with an alternative method in which all the items are first presented to respondents and, only after all items have been presented, does the valuation begin. It is hypothesized that this alternative sequence will reduce order effects. In addition, a battery of questions on environmental attitudes is added to the survey to better explain any variation in response patterns. Subjects are recruited by phone (random digit dial) and offered incentive payment (approximately $50) to come to the survey firm location. Subjects come in groups of about 15-20. There is a moderator for each session. Subjects are presented with cards. The moderator leads subjects through a series of questions. The session lasts about 60-75 minutes.
Study C. This study replicates Fischhoff, et al. (1993), which found a lack of sensitivity to scale. The replication probes several features of the original study: Do people respond to what they perceive as the cost of the program, rather than formulating a value? Do attitudes such as altruism influence patterns of response? How do attitudes to the effectives of the specific program affect response patterns?
This study is a general public telephone survey via random digit dial in a given state (e.g., Ohio).
The three surveys were conducted in January 2005, the data were cleaned and turned over by the survey company at the end of February 2005, and an econometric analysis is underway.
The preliminary results are very promising. In Study A, it appears that the scope insensitivity disappears when percentages are used. In Study B, it appears that the sequence effects are mitigated greatly when all alternatives are presented ahead of time before any valuation is conducted. In Study C, it appears that, for many respondents, response to an open-ended valuation question is influenced by assessment of what the item might cost. There appear to be some respondents, however, with quite well-defined characteristics who are altruistic, and this is reflected in their valuation behavior.
The data analysis is still underway and aims to refine and extend the preliminary results listed above.
Future Activities:
We will seek a no-cost extension through June 30, 2006, to complete the data analysis and to finalize three journal articles for submission for publication. The project will be completed once these articles have been submitted for publication.
References:
Boyle K, Desvousges W, Johnson R, Dunford R, Hudson S. An investigation of part-whole biases in contingent-valuation studies. Journal of Environmental Economics and Management 1994;27(1):64-83.
Payne JW, Schkade DA, Desvousges WH, Aultman C. Valuation of multiple environmental programs. Journal of Risk and Uncertainty 2000;21(1):95-115.
Fischhoff B, Quadrel MJ, Kamlet M, Loewenstein G, Dawes R, Fischbeck P, Klepper S, Leland J, Stroh P. Embedding effects: stimulus representation and response mode. Journal of Risk and Uncertainty 1993;6(3):211-234.
Journal Articles:
No journal articles submitted with this report: View all 5 publications for this projectSupplemental Keywords:
embedding, stated preference, SP, SP surveys, scope effects, insensitivity to scope, relative effects, proportional effects, absolute effects, survey instrument, survey location, order effects, random digit dial, valuation behavior,, RFA, Scientific Discipline, Economic, Social, & Behavioral Science Research Program, Health, Geographic Area, Health Risk Assessment, State, Susceptibility/Sensitive Population/Genetic Susceptibility, Environmental Monitoring, Allergens/Asthma, Ecological Risk Assessment, decision-making, Children's Health, genetic susceptability, Economics & Decision Making, Social Science, social psychology, surveys, behavioral effects, asthma, contingent valuation, sensitive populations, social impact analysis, valuation, morbidity, random utility model, air toxics, economic valuation, decision analysis, incentives, ozone, behavioral assessment, airway disease, risk perception, children's health values, preference formation, air pollution, environmental values, survey, airway inflammation, children, willingness to pay (WTP), adult valuation of children's health, asthmatic children, psychological attitudes, environmental health hazard, children's environmental health, environmentally caused disease, stated preference, willingness to pay, California (CA), economic objectives, behavior reactions, asthma morbidityProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.