Cameron, Trudy Ann

Permanent URI for this collection

https://hdl.handle.net/1794/3686

Browse

Browsing Cameron, Trudy Ann by Issue Date

Filter results by year or month
Now showing 1 - 11 of 11
  • Thumbnail Image
    ItemOpen Access
    Scenario Adjustment in Stated Preference Research
    (University of Oregon, Dept of Economics, 2009-11-22) Cameron, Trudy Ann; DeShazo, J. R.; Johnson, Erica H.
    Stated preference (SP) survey methods have been used increasingly to assess willingness to pay for a wide variety of non-market goods and services, including reductions in risks to life and health. Poorly designed SP studies are subject to a number of well-known biases, but many of these biases can be minimized when they are anticipated ex ante and accommodated in the study’s design or during data analysis. We identify another source of potential bias, which we call “scenario adjustment,” where respondents assume that the substantive alternative(s) in an SP choice set, in their own particular case, will be different than the survey instrument describes. We use an existing survey, developed to ascertain willingness to pay for private health-risk reduction programs, to demonstrate a strategy to control and correct for scenario adjustment in the estimation of willingness to pay. This strategy involves data from carefully worded follow-up questions and ex post econometric controls for each respondent’s subjective departures from the intended choice scenario. Our research has important implications for the design of future SP surveys.
  • Thumbnail Image
    ItemOpen Access
    Differential Attention to Attributes in Utility-theoretic Choice Models
    (University of Oregon, Dept of Economics, 2008-10) Cameron, Trudy Ann; DeShazo, J. R.
    We show in a theoretical model that benefits of allocating additional attention to evaluating the marginal attribute with in choice set depend upon the expected utility loss from making a suboptimal choice as a result of ignoring that incremental attribute. Guided by this analysis, we then develop a very general and practical empirical method for measuring the individual's propensity to attend to attributes. As a proof of concept, we offer an empirical example of our method using a conjoint analysis of demand for programs to reduce health risks. Our results suggest that respondents differentially allocate attention across attributes, as a function of the mix of attribute levels in a choice set. This behavior can cause researchers who fail to model attention allocation to incorrectly estimate the marginal utilities derived from selected attributes. This illustrative example is a first attempt to implement an attention-corrected choice model with a sample of field data from a conjoint choice experiment.
  • Thumbnail Image
    ItemOpen Access
    Evidence of Environmental Migration: Housing values alone may not capture the full effects of local environmental disamenities
    (University of Oregon, Dept of Economics, 2005-01-01) Cameron, Trudy Ann; McConnaha, Ian
    In hedonic property value models, economists typically assume that changing perceptions of environmental risk should be captured by changes in housing prices. However, for long-lived environmental problems, we find that many other features of neighborhoods seem to change as well, because households relocate in response to changes in perceived environmental quality. We consider spatial patterns in census variables over three decades in the vicinity of four Superfund sites. We find many examples of moving and staying behavior, inferred from changes in the relative concentrations of a wide range of socio-demographic groups in census tracts near the site versus farther away.
  • Thumbnail Image
    ItemOpen Access
    An Empirical Model of Demand for Future Health States when Valuing Risk-Mitigating Programs
    (University of Oregon, Dept. of Economics, 2004-03) Cameron, Trudy Ann; DeShazo, J. R.
    We develop a structural option price model in which individuals choose among competing risk-mitigating programs to alter their probability of experiencing future years in various degraded health states. The novel aspects of this model include separate estimates of the marginal utilities of avoiding years of morbidity and lost life-years. With these marginal utilities, we may evaluate a broad spectrum of probabilistic health outcomes over any period of an individual’s future life. The model also reduces potential biases associated with singleperiod, single-risk models typically used to produce estimates of the Value of a Statistical Life (VSL) by allowing individuals to substitute risk mitigation across competing sources of risk and across future years of their lives. We evaluate this model using data from a national survey that contains a choice experiment on demand for the mitigation of illness-specific risks.
  • Thumbnail Image
    ItemOpen Access
    Superfund Taint and Neighborhood Change: Ethnicity, Age Distributions, and Household Structure
    (University of Oregon, Dept. of Economics, 2003-12) Cameron, Trudy Ann; Crawford, Graham D.
    Certain sociodemographic groups often seem to be relatively more concentrated near environmental hazards than in the surrounding community. It is well-known that snapshot cross-sectional statistical analyses cannot reveal how residential mobility for these different groups reacts to changing public perceptions of environmental hazards. Decennial panel data over four census periods, for census tracts surrounding seven different urban Superfund localities, allow us to examine how ethnicities, the age distribution and family structure vary over time with distance from these major environmental disamenities. If the slope of the distance profile decreases over time, the group in question could be argued to be “coming to the nuisance.” We find a lot of statistically significant movement, including some evidence of minority move-in and increasing relative exposure of children, especially those in singleparent households. However, it appears to be hard to make generalizations, across localities, about the mobility patterns for different groups. This heterogeneity may account for the difficulty other researchers have experienced in identifying systematic effects in data that are pooled across different environmental hazards. Changes over time in the sociodemographic mix near Superfund sites may also help explain differences in the extent to which housing prices rebound after cleanup commences.
  • Thumbnail Image
    ItemOpen Access
    Appendices to Superfund Taint and Neighborhood Change: Ethnicity, Age Distributions, and Household Structure
    (University of Oregon, Dept. of Economics, 2003-12) Cameron, Trudy Ann; Crawford, Graham D.
    Certain sociodemographic groups often seem to be relatively more concentrated near environmental hazards than in the surrounding community. It is well-known that snapshot cross-sectional statistical analyses cannot reveal how residential mobility for these different groups reacts to changing public perceptions of environmental hazards. Decennial panel data over four census periods, for census tracts surrounding seven different urban Superfund localities, allow us to examine how ethnicities, the age distribution and family structure vary over time with distance from these major environmental disamenities. If the slope of the distance profile decreases over time, the group in question could be argued to be “coming to the nuisance.” We find a lot of statistically significant movement, including some evidence of minority move-in and increasing relative exposure of children, especially those in singleparent households. However, it appears to be hard to make generalizations, across localities, about the mobility patterns for different groups. This heterogeneity may account for the difficulty other researchers have experienced in identifying systematic effects in data that are pooled across different environmental hazards. Changes over time in the sociodemographic mix near Superfund sites may also help explain differences in the extent to which housing prices rebound after cleanup commences.
  • Thumbnail Image
    ItemOpen Access
    Directional Heterogeneity in Distance Profiles in Hedonic Property Value Models
    (University of Oregon, Dept. of Economics, 2003-07-01) Cameron, Trudy Ann
    Failure to allow for directional heterogeneity can obscure otherwise statistically significant distance effects in hedonic property value models. If ambient pollution data are unavailable, researchers often rely upon distance from a point source of pollution as a proxy for ambient environmental quality. However, damages from all types of point-source disamenities may exhibit directional heterogeneity. We generalize conventional distance models to allow for directional effects and show that commonly used linear and quadratic spatial trend variables capture directional heterogeneity in a manner that has not previously been recognized. Appropriate spatial models can also inform the social planner’s problem of optimal allocation of source reduction across polluters. When independently calibrated tranport functions are not available, individual properties can be viewed as ambient receptor sites. Hedonic models can yield estimates of the product of marginal social damages from ambient concentrations and the change in ambient concentration per unit of emissions from each source. Optimal emissions depend upon the spatial distribution of all affected properties relative to each source, the parameters of the hedonic model, and marginal abatement costs.
  • Thumbnail Image
    ItemOpen Access
    Eliciting Individual-Specific Discount Rates
    (University of Oregon, Dept. of Economics, 2003-01-01) Cameron, Trudy Ann; Gerdes, Geoffrey R.
    Longstanding debate over the appropriate social discount rate for public projects stems from our lack of knowledge about how individual discount rates vary across people and across choice contexts. Using a sample of roughly 15,000 choices by over 2000 individuals, we estimate utility theoretic models concerning private tradeoffs involving money over time that reveal individual specific discount rates. We control for experimentally differentiated choice scenarios, sociodemographic heterogeneity, and elicitation formats, and complex forms of heteroscedasticity. Statistically significant heterogeneity in discount rates is quantified for both an exponential discounting model and a competing hyperbolic model, but neither specification clearly dominates.
  • Thumbnail Image
    ItemOpen Access
    Individual Option Prices for Climate Change Mitigation
    (University of Oregon, Dept. of Economics, 2002-07-20) Cameron, Trudy Ann
    Willingness to pay for climate change mitigation depends on people's perceptions about just how bad things will get if nothing is done. Individual subjective distributions for future climate conditions are combined with stated preference discrete choice data over alternative climate policies to estimate individual option prices (the appropriate ex ante welfare measure in the face of uncertainty) for climate change mitigation. We find significant scope effects in the estimated option prices according to both expected conditions and degree of uncertainty.
  • Thumbnail Image
    ItemOpen Access
    Test of Choice Set Misspecification for Discrete Models of Consumer Choice
    (University of Oregon, Dept. of Economics, 2001-11-05) DeShazo, J. R.; Cameron, Trudy Ann; Saenz, Manrique, 1971-
    We develop and evaluate a test of choice set misspecification for a multinomial logit choice model. This test determines whether the choice set designated by the researcher mistakenly assigns relevant substitutes to the numeraire good. We develop this test by generalizing the traditional McFadden-type conditional logit model to evaluate whether the traditional model is conditioned on an overly restrictive set of substitution possibilities. The test has a convenient feature: while it requires information on potentially relevant, but omitted, substitute goods, it does not require the researcher to observe consumers? choices among these omitted potential substitutes if they select the numeraire good (which contains these omitted substitutes). A comparison of the traditional multinomial logit choice model and our more general model suggests that choice set misspecification may produce biased parameters that distort welfare estimates to a consequential extent.
  • Thumbnail Image
    ItemOpen Access
    Updating Subjective Risks in the Presence of Conflicting Information: An Application to Climate Change
    (University of Oregon, Dept. of Economics, 2001-07-14) Cameron, Trudy Ann
    Willingness to support public programs for risk management often depends on individual subjective risk perceptions in the face of uncertain science. As part of a larger study concerning climate change, we explore individual updated subjective risks as a function of individual priors, the nature of external information, and individual attributes. We examine several rival hypotheses about how subjective risks change in the face of new information (Bayesian updating, alarmist learning, and ambiguity aversion). The source and nature of external information, as well as its collective ambiguity, can have varying effects across the population, in terms of both expectations and uncertainty.