Alternative Approaches to Incorporating the Opportunity Cost of Time in Recreation Demand Models

The importance of accounting for a respondent’s travel time in recreation demand models is well established. In practice, most analysts use a fixed fraction of the respondent’s wage rate to value travel time. However, other approaches have been suggested in the literature. In this paper revealed and stated preference data on Iowa wetland usage is used to explore various specifications of travel time. It is shown that the choice of a particular specification has a direct impact on welfare estimates as well as the consistency between revealed and stated preference data.

Valuing Resource Access with Seminonparametric Techniques: An Application to Clear Lake

The focus of this investigation is three-fold. First, seminonparametric techniques are considered in order to avoid the pitfall of imparting bias on value estimates. Second, the efficacy of seminonparametric techniques are explored in an empirical setting by valuing recreational access at Clear Lake, Iowa. Finally, a technique from Eastwood and Gallant (1991) is adapted and applied to the count data model

Exploring Respondent’s Perception of Bid Precision in Non-Market Valuation

Bid design is an important component of the nonmarket valuation process. To date, no research has been done on the possible effects of using round dollar amounts. It seems reasonable to believe that respondents may respond to round dollar amounts differently than they would respond to bids that include both dollar and cent amounts. One possibility is that the respondent may infer that the dollar/cent bids are more precise estimates of the true cost than the round dollar amount, and therefore put more thought into their response to survey questions. In order to explore this idea, we test whether the use of a precise versus imprecise bid design influences respondent’s willingness to pay. In particular, our sample of survey recipients was stratified into two groups based on whether they were presented with imprecise or precise bids (round dollar bids or dollar/cent bids). Precise bids were generated by adding or subtracting a randomly-drawn number of cents (between -200 and +200 cents) to each of the imprecise bid levels. We explore this issue in the context of a valuation project concerned with The Battle of Lexington State Historic Site in Lexington, MO.

Testing for the Internal Consistency of Choice Experiments Using Explicit Rankings of Quality Attributes

Choice experiments (CEs) are an increasingly important tool in the environmental valuation literature because of their ability to deal with multifaceted environmental issues and their basis in random utility theory. One particularly useful aspect of the CE method is that it allows researchers to estimate marginal rates of substitution between an environmental resource’s various attributes. These marginal rates of substitution provide an implicit ranking of the attributes, which can be compared with other ranking mechanisms. In this paper we describe a method for testing for the internal consistency of choice experiments by comparing the implicit attribute ranking generated by a CE with that generated by an explicit attribute-ranking exercise. The analysis uses data gathered through a unique survey in which respondents completed both a CE exercise and an attribute-ranking exercise indicating their preferences over pollution abatement and water quality improvement strategies for a freshwater lake in north-central Iowa. Comparisons are made on a sample-wide basis as well as an individual basis.Environmental valuation, choice experiments, internal consistency

Stochastic Dominance, Entropy and Biodiversity Management

In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case.

Stochastic Dominance, Entropy and Biodiversity Management

In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case. Key Words: Stochastic Dominance, Entropy, Biodiversity Management

The Demand For NFL Attendance: A Rational Addiction Model

This paper examines the demand for attendance at National Football League (NFL) games using a rational addiction model to test the hypothesis that professional football displays the properties of a habit-forming good.  Rational addiction theory suggests that past and future consumption play a part in determining the current period’s consumption for habit-forming goods.  Additionally, we postulate the behavioral implications of profit-maximizing ticket pricing behavior by NFL teams.  Previous studies have been unable to detect pricing power by NFL teams.  Our model of pricing power allows us to identify theoretically- anticipated pricing behavior.  A pooled data set is collected using statistics from each NFL team from the 1983 to the 2008 seasons.  Current attendance is modeled as a function of team specific variables, including past and future attendance, ticket price, and team performance.  The model is estimated using Two-Stage Least Squares (2SLS).  We also treat the censored nature of ticket demand as NFL teams frequently experience sell-outs.  It is found that past and future attendance, winning percentage, the age of the stadium in which a team plays, and own-price demand elasticity influence attendance.  The fact that coefficients for past and future attendance are positive and significant in this analysis lends support to the notion that NFL fans display characteristics of rational addiction in their consumption behavior.  Further, we find evidence to support profit-maximizing behavior in ticket sales

Bosonic Excitations in Random Media

We consider classical normal modes and non-interacting bosonic excitations in disordered systems. We emphasise generic aspects of such problems and parallels with disordered, non-interacting systems of fermions, and discuss in particular the relevance for bosonic excitations of symmetry classes known in the fermionic context. We also stress important differences between bosonic and fermionic problems. One of these follows from the fact that ground state stability of a system requires all bosonic excitation energy levels to be positive, while stability in systems of non-interacting fermions is ensured by the exclusion principle, whatever the single-particle energies. As a consequence, simple models of uncorrelated disorder are less useful for bosonic systems than for fermionic ones, and it is generally important to study the excitation spectrum in conjunction with the problem of constructing a disorder-dependent ground state: we show how a mapping to an operator with chiral symmetry provides a useful tool for doing this. A second difference involves the distinction for bosonic systems between excitations which are Goldstone modes and those which are not. In the case of Goldstone modes we review established results illustrating the fact that disorder decouples from excitations in the low frequency limit, above a critical dimension $d_c$, which in different circumstances takes the values $d_c=2$ and $d_c=0$. For bosonic excitations which are not Goldstone modes, we argue that an excitation density varying with frequency as $\rho(\omega) \propto \omega^4$ is a universal feature in systems with ground states that depend on the disorder realisation. We illustrate our conclusions with extensive analytical and some numerical calculations for a variety of models in one dimension

Genome-wide association analysis of thirty one production, health, reproduction and body conformation traits in contemporary U.S. Holstein cows

<p>Abstract</p> <p>Background</p> <p>Genome-wide association analysis is a powerful tool for annotating phenotypic effects on the genome and knowledge of genes and chromosomal regions associated with dairy phenotypes is useful for genome and gene-based selection. Here, we report results of a genome-wide analysis of predicted transmitting ability (PTA) of 31 production, health, reproduction and body conformation traits in contemporary Holstein cows.</p> <p>Results</p> <p>Genome-wide association analysis identified a number of candidate genes and chromosome regions associated with 31 dairy traits in contemporary U.S. Holstein cows. Highly significant genes and chromosome regions include: BTA13's <it>GNAS </it>region for milk, fat and protein yields; BTA7's <it>INSR </it>region and BTAX's <it>LOC520057 </it>and <it>GRIA3 </it>for daughter pregnancy rate, somatic cell score and productive life; BTA2's <it>LRP1B </it>for somatic cell score; BTA14's <it>DGAT1-NIBP </it>region for fat percentage; <it>BTA1</it>'s <it>FKBP2 </it>for protein yields and percentage, BTA26's <it>MGMT </it>and BTA6's <it>PDGFRA </it>for protein percentage; BTA18's 53.9-58.7 Mb region for service-sire and daughter calving ease and service-sire stillbirth; BTA18's <it>PGLYRP1</it>-<it>IGFL1 </it>region for a large number of traits; BTA18's <it>LOC787057 </it>for service-sire stillbirth and daughter calving ease; BTA15's <it>CD82</it>, BTA23's <it>DST </it>and the <it>MOCS1</it>-<it>LRFN2 </it>region for daughter stillbirth; and BTAX's <it>LOC520057 </it>and <it>GRIA3 </it>for daughter pregnancy rate. For body conformation traits, BTA11, BTAX, BTA10, BTA5, and BTA26 had the largest concentrations of SNP effects, and <it>PHKA2 </it>of BTAX and <it>REN </it>of BTA16 had the most significant effects for body size traits. For body shape traits, BTAX, BTA19 and BTA3 were most significant. Udder traits were affected by BTA16, BTA22, BTAX, BTA2, BTA10, BTA11, BTA20, BTA22 and BTA25, teat traits were affected by BTA6, BTA7, BTA9, BTA16, BTA11, BTA26 and BTA17, and feet/legs traits were affected by BTA11, BTA13, BTA18, BTA20, and BTA26.</p> <p>Conclusions</p> <p>Genome-wide association analysis identified a number of genes and chromosome regions associated with 31 production, health, reproduction and body conformation traits in contemporary Holstein cows. The results provide useful information for annotating phenotypic effects on the dairy genome and for building consensus of dairy QTL effects.</p