Controlling for the effects of information in a public goods discrete choice model

This paper develops a reduced form method of controlling for differences in information sets of subjects in public good discrete choice models, using stated preference data. The main contribution of our method comes from accounting for the effect of information provided during a survey on the mean and the variance of individual-specific scale parameters. In this way we incorporate both scale heterogeneity as well as observed and unobserved preference heterogeneity to investigate differences across and within information treatments. Our approach will also be useful to researchers who want to combine stated preference data sets while controlling for scale differences. We illustrate our approach using the data from a discrete choice experiment study of a biodiversity conservation program and find that the mean of individual-specific scale parameters and its variance in the sample is sensitive to the information set provided to the respondents

δ13C tracing of dissolved inorganic carbon sources in major world rivers

δ13C tracing of dissolved inorganic carbon sources in major world river

The Effects of Experience on Preference Uncertainty: Theory and Empirics for Public and Quasi-Public Goods

This paper develops a model of demand estimation in which consumers learn about their true preferences through consumption experiences. We develop a theoretical model of Bayesian updating, perform comparative statics over the model, and show how the theoretical model can be consistently incorporated into a reduced form econometric model. We then estimate the model using data collected for two quasi experience with a good will make consumers more certain over their preferences in both mean and variance are supported in each case.‐public goods. We find that the predictions of the theoretical exercise that additiona

What is the causal impact of information and knowledge in stated preference studies?

This paper reports the results of a stated preference experiment designed to test how information about a good’s attributes provided in a survey affects knowledge, and how knowledge affects preferences for that good. A novel experimental design allows us to elicit subjects’ ex ante knowledge levels about a public good’s attributes, exogenously vary how much new objective information about these attributes we provide to subjects, elicit subjects’ valuation for the good, and elicit posterior knowledge states about the same attributes. We find evidence of incomplete learning and fatigue: as subjects are told more information, their marginal learning rates decrease. Consistent with previous work, ex ante knowledge does affect stated willingness to pay. However, we find no significant marginal impact of knowledge on the mean nor the variance of willingness to pay for changes in the environmental good conditional on ex ante knowledge. Our results are consistent with a number of conceptual models of information processing and preferences, including confirmation bias, costly search, and timing differences in learning and preference formation

SEDP-2014-05

In this study we elicit agents' prior information set regarding a public good, exogenously give information treatments to survey respondents and subsequently elicit willingness to pay for the good and posterior information sets. The design of this field experiment allows us to perform theoretically motivated hypothesis testing between different updating rules: non-informative updating, Bayesian updating, and incomplete updating. We find causal evidence that agents imperfectly update their information sets. We also field causal evidence that the amount of additional information provided to subjects relative to their pre-existing information levels can affect stated WTP in ways consistent overload from too much learning. This result raises important (though familiar) issues for the use of stated preference methods in policy analysis

Mineralogical controls on the distribution of platinum-group elements and gold in the Afton porphyry deposits, Kamloops, British Columbia

Publisher's version/PDFAbstract of a presentation made at Atlantic Universities Geological Conference 2008, October 23-25, 200

SEDP-2014-04

This paper compares how increases in experience versus increases in knowledge about a public good affect willingness to pay (WTP) for its provision. This is challenging because while consumers are often certain about their previous experiences with a good, they may be uncertain about the accuracy of their knowledge. We therefore design and conduct a field experiment in which treated subjects receive a precise and objective signal regarding their knowledge about a public good before estimating their WTP for it. Using data for two different public goods, we show qualitative equivalence of the effect of knowledge and experience on valuation for a public good. Surprisingly, though, we find that the causal effect of objective signals about the accuracy of a subject's knowledge for a public good can dramatically affect their valuation for it: treatment causes an increase of $150-$200 in WTP for well-informed individuals. We find no such effect for less informed subjects. Our results imply that WTP estimates for public goods are not only a function of true information states of the respondents but beliefs about those information states

Superior infectivity for mosquito vectors contributes to competitive displacement among strains of dengue virus

<p>Abstract</p> <p>Background</p> <p>Competitive displacement of a weakly virulent pathogen strain by a more virulent strain is one route to disease emergence. However the mechanisms by which pathogens compete for access to hosts are poorly understood. Among vector-borne pathogens, variation in the ability to infect vectors may effect displacement. The current study focused on competitive displacement in dengue virus serotype 3 (DENV3), a mosquito-borne pathogen of humans. In Sri Lanka in the 1980's, a native DENV3 strain associated with relatively mild dengue disease was displaced by an invasive DENV3 strain associated with the most severe disease manifestations, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), resulting in an outbreak of DHF/DSS. Here we tested the hypothesis that differences between the invasive and native strain in their infectivity for <it>Aedes aegypti </it>mosquitoes, the primary vector of DENV, contributed to the competitive success of the invasive strain</p> <p>Results</p> <p>To be transmitted by a mosquito, DENV must infect and replicate in the midgut, disseminate into the hemocoel, infect the salivary glands, and be released into the saliva. The ability of the native and invasive DENV3 strains to complete the first three steps of this process in <it>Aedes aegypti </it>mosquitoes was measured <it>in vivo</it>. The invasive strain infected a similar proportion of mosquitoes as the native strain but replicated to significantly higher titers in the midgut and disseminated with significantly greater efficiency than the native strain. In contrast, the native and invasive strain showed no significant difference in replication in cultured mosquito, monkey or human cells.</p> <p>Conclusion</p> <p>The invasive DENV3 strain infects and disseminates in <it>Ae. aegypti </it>more efficiently than the displaced native DENV3 strain, suggesting that the invasive strain is transmitted more efficiently. Replication in cultured cells did not adequately characterize the known phenotypic differences between native and invasive DENV3 strains. Infection dynamics within the vector may have a significant impact on the spread and replacement of dengue virus lineages.</p