The effects of direct experience on consumer product evaluation

The effects of different sales strategies on consumer product evaluation were investigated. It was expected that direct product experience could decrease economic product valuation. Experiments 1 and 2 studied the effects of product trials and money-back guarantees on consumer willingness to pay (WTP). It appeared that WTP was significantly lower after a product trial than with a money-back guarantee or normal sale. In Experiment 3 a structural equation model showed that product trials had a positive effect on attitude toward the product. Also, a negative effect on WTP was found when the effect was measured directly, but a positive effect when the effect was measured indirectly (through attitude).     

A NEW CLASS OF MODELS FOR THE DISCRIMINANT PROBLEM

Discriminant analysis is relevant to business decision making in a variety of contexts, such as when one decides to make or buy a specified component, fund a venture project, or hire a particular person. Potential applications in artificial intelligence, particularly in the area of pattern recognition, have further underscored the importance of the field. A recent innovation in discriminant analysis is provided by special linear programming (LP) models, which offer attractive alternatives to classical statistical approaches. The scope of application in which discriminant analysis can be advantageously employed is broadened by the flexibility to tailor parameters in the LP approaches to reflect diverse goals and by the power to explore the sensitivity of these parameters. In spite of the promise of the LP formulations, however, limitations to their effectiveness have been uncovered in certain settings. A recent advance involving a normalization construct removes some of the limitations but entails solving the LP model twice (to allow for different signs of a normalization constant) and does not yield equivalent solutions for different rotations of the problem data. This paper introduces a new model and a new class of normalizations that remedy both remaining limitations, making it possible to take advantage of the modeling capabilities of the LP formulations without the attendant shortcomings encountered by earlier investigations. Our development shows by empirical testing and illustrative analysis that the quality of solutions from LP discriminant approaches is more favorable (relative to the classical model) than previously supposed.     

USING CONJOINT ANALYSIS TO PREDICT TRIAL AND REPEAT-PURCHASE PATTERNS OF NEW FREQUENTLY PURCHASED PRODUCTS*

A new approach is proposed to evaluate new-product opportunities. This approach uses the distribution of brand-purchase probability of the new product over a population of potential customers and the outputs from conjoint analysis. The heterogeneous distribution of brand-purchase probability is expressed by a beta binomial brand-choice model compounded with a negative binomial product-class purchase-incidence model. The resulting model provides a way to predict trial and repeat-purchase patterns of new-product concepts. The paper discusses the development of the model. It also discusses issues of measurement, estimation, testing, and implementation of the proposed approach based on actual empirical data.     

Urban land cover decreases the occurrence of a wetland endemic mammal and its associated vegetation

Urbanization and other land cover changes have been particularly detrimental to wetlands throughout the planet. One wetland specialist that may be sensitive to land cover changes surrounding wetlands is the round-tailed muskrat (Neofiber alleni; hereafter RTM). The RTM is a wetland obligate rodent that appears to have declined over the last half century and is a species of concern in Florida, where it is a near endemic. To determine if urbanization or other land cover influenced the distribution of RTMs we took a multi-scaled approach to examine the occurrence of RTMs and their associated vegetation in North-Central Florida. We detected RTMs on 19 of 72 sample plots and used a Classification And Regression Tree (CART) to determine that dogfennel (Eupatorium capillifolium) was negatively associated with RTMs and maidencane (Panicum hemitomon) was positively associated with their occurrence on sampling plots. Examining the influence of landscape composition for 2 km surrounding our plots we found that RTM occurrence was negatively related to urban land cover. Further, we found that dogfennel increased and maidencane decreased as urbanization increased in the surrounding landscape. Our research suggests that conservation of RTMs and their associated vegetation should focus on limiting urban sprawl at least within 2 km of wetlands.     

Urban habitats can affect body size and body condition but not immune response in amphibians

Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology.     

Nitrogen retention and loss in unfertilized lawns across a light gradient

A desirable function for terrestrial urban ecosystems is the mitigation of nitrogen (N) pollution associated with cities and suburbs. To assist in maximizing this function, identifying locations of sources and sinks of N in the urban environment is crucial to inform management strategies. Lawns are an extensive land cover in urbanized landscapes, and in general, they have demonstrated the capacity to function as a sink for N inputs. How N is cycled by lawns, however, is likely not uniform across the physical heterogeneity or management activities that exist in lawns. We investigated the influence of heterogeneity in light availability on N cycling in lawns that were irrigated but not fertilized. Light availability is affected by tree canopy and built structures and is, therefore, heterogeneous both within individual lawns and among lawns. Light is expected to control N retention and loss through effects on primary productivity. We experimentally examined N regulation over one calendar year by measuring net primary production (NPP), N retention using an isotopic tracer, and N leaching in existing unfertilized lawns under heterogeneous light conditions. We used a budgetary approach to estimate gaseous N loss which we assume is primarily via denitrification. Light functioned as a limiting resource for primary productivity. From low to high light conditions, annual NPP increased 177 to 430 g C?m^?2?y^?1 and retention of N isotope tracer increased from 50 to 65% as a result of increased retention in plants. Nitrate leaching losses were low overall and were not affected by light levels. Light availability regulated the fate of N inputs and unfertilized lawns may function as substantial sinks for reactive N through storage in the terrestrial system and N loss by denitrification. However, whether or not denitrification is generally an N sink will depend on the ratio of non-reactive (i.e., N₂) to reactive (i.e., N₂O, NO) denitrification products. Overall, we find that effective strategies for managing N sources and sinks in cities will likely need to consider light availability, particularly in systems receiving water subsidies via irrigation.     

Patterns of pollinator turnover and increasing diversity associated with urban habitats

The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.     

Use of Poset Theory with Big Datasets: A New Proposal Applied to the Analysis of Life Satisfaction in Italy

The aim of this work is to propose a tool for measuring a complex concept, and to apply it to big sets of data measured on ordinal and/or dichotomous scales. An important field of application are subjective data, that are often based on opinions or personal evaluations. Many national and international surveys employ this kind of data, measured among thousand of individuals. Thanks to the use of the “average rank” as a synthetic measure of a complex concept, we believe that poset theory could be a very useful approach for dealing with ordinal data avoiding the use of scaling procedures. Because classic poset approaches are at their best when applied to few data at a time, our idea is based on a procedure for sampling units from a big population using a simple criterion to summarize the resulting values appropriately. Applying the central limit theorem enables a comparison of the results obtained from different groups using statistical tests on the means. We used our Height of Groups by Sampling (HOGS) method to compare the average rank among groups that are defined by one or more socio-demographic variables influencing the level of the complex concept we wish to measure. The application of the HOGS procedure to life satisfaction in Italy generated convincing results, revealing significant differences between regions, genders and levels of formal education. We compared the results given by HOGS with the non linear principal component analysis and obtain an easy readable output with convincing precision and accuracy; we are confident that the HOGS procedure can be applied to many other concepts investigated in the social sciences.