What Makes Consumers Purchase Fresh Eggs in Supermarkets: The Effect of Unrealistic Choice Set Matters

Eggs are the crucial component of daily meals for almost everyone in Taiwan, while the multi-attributes of fresh egg products generate the challenges of marketing and promotions in supermarkets. This study analyzes the market segmentation and consumer willingness-to-pay (WTP) for fresh egg attributes (i.e., color, traceability, animal welfare, brand, and price). In particular, the effect of the unrealistic choice set is considered in this study. The data collection was distributed near markets, schools, and train stations across Taiwan from July to September in 2020. A total of 1115 valid responses were collected, and the Latent Class Model was used. Results show that fresh egg products in supermarkets reveal a strong preference for animal welfare label with the highest WTP, which is about 64.2 NT$ (≈US$ 2.29). Furthermore, traceability label, farm brand, and brown-color egg still exhibit positive WTP of about 33.4 NT$ (≈US$ 1.19), 32.6 NT$ (≈US$ 1.16), and 32.5 NT$ (≈US$ 1.16) in supermarkets, respectively. However, including the unrealistic choice set can potentially alter the final outcomes, and it provides a good example for researchers who may have the same situation. This research helps to know more about the complexity of attributes for fresh egg products in supermarkets, so marketers would be able to adopt the effective marketing strategies for fresh egg products in supermarkets.

Assessing Parental Preferences Regarding a Plant-Based Game for Educating Children about More Sustainable and Healthier Diets

Environmental damage or health concerns related to diet are some alarming consequences of our behaviour in the near future. Consumers can make a difference depending on their eating behaviour and conscientiousness about minimizing environmental damage. One way to make children more aware of the environment and induce them to eat healthier food in the future might be educational games where they could learn the importance of the environment and the effect of the food they eat on their health status. In this study, we investigated parental behaviour when feeding their children and their willingness to pay for a game product with educational and eating functions. The sample consisted of 300 parents of children aged from 4 to 12. A hypothetical choice experiment has been used and a latent class model estimated the parents’ preferences for a plant-based product game carrying two attributes, namely, the price and narrative context of the game The results indicated that parents were willing to pay more for a product with a storybook related to healthy eating habits or recycling than one with no storybook. Moreover, two dominant feeding styles in households were found: indulgent parents and uninvolved parents. This alternative approach is oriented toward educating people from the early stages of their lives, creating a favourable environment for the development of preferences for healthier food.

Living in the 'liveable' city: Housing, Neighbourhood, and Transport Preferences in New Zealand cities

<p>This thesis investigates preferences for housing, neighbourhoods, and transport in Auckland, New Zealand, supplemented by a comparison with similar research in Wellington and Hamilton. The topic is significant for New Zealand as there is an increasingly urban population, and the interconnected areas of urban form and transport can help the country reduce carbon emissions and provide a healthier, more enjoyable lifestyle for its people. The influence of residents’ preferences and their relationship with urban form on achieving compact city development is investigated. Historical and current planning rules and policies provide context for an analysis of how urban planning, preferences, and location and travel choices interact. Auckland’s housing and transport policies show a pattern of path dependency: decisions favouring greenfield development, sprawling low-density suburbs, and car-centred transport have driven subsequent investments and influenced the ease of using alternative transport modes. Such rules have also reduced the availability of housing in accessible, medium- to high-density neighbourhoods and may have contributed to the rising costs of this type of housing. A stated choice survey of 3,285 Auckland households was conducted to investigate the extent to which there is an unmet demand for compact development and alternatives to car travel. Using the survey results, a multinomial latent class model was developed to examine the preferences of households and the trade-offs they may be willing to make when choosing where to live. This type of model allows for identification of preference groups as a means of understanding the heterogeneity of preferences across the population. There was an unmet demand for accessible, medium-density housing, with some households willing to trade off dwelling size and neighbourhood type for higher accessibility or lower prices. The study also found that more people currently drive than would prefer to, with long journey times, safety concerns, unreliable services, and a lack of infrastructure acting as barriers to active and public transport. Households preferring low density are more likely to occupy their preferred dwelling type and be able to use their preferred transport mode. In contrast, those preferring high accessibility or driven by price are more likely to experience a mismatch between their preferred and current dwelling type, and are less likely to be able to use their preferred transport mode.</p>

Living in the 'liveable' city: Housing, Neighbourhood, and Transport Preferences in New Zealand cities

<p>This thesis investigates preferences for housing, neighbourhoods, and transport in Auckland, New Zealand, supplemented by a comparison with similar research in Wellington and Hamilton. The topic is significant for New Zealand as there is an increasingly urban population, and the interconnected areas of urban form and transport can help the country reduce carbon emissions and provide a healthier, more enjoyable lifestyle for its people. The influence of residents’ preferences and their relationship with urban form on achieving compact city development is investigated. Historical and current planning rules and policies provide context for an analysis of how urban planning, preferences, and location and travel choices interact. Auckland’s housing and transport policies show a pattern of path dependency: decisions favouring greenfield development, sprawling low-density suburbs, and car-centred transport have driven subsequent investments and influenced the ease of using alternative transport modes. Such rules have also reduced the availability of housing in accessible, medium- to high-density neighbourhoods and may have contributed to the rising costs of this type of housing. A stated choice survey of 3,285 Auckland households was conducted to investigate the extent to which there is an unmet demand for compact development and alternatives to car travel. Using the survey results, a multinomial latent class model was developed to examine the preferences of households and the trade-offs they may be willing to make when choosing where to live. This type of model allows for identification of preference groups as a means of understanding the heterogeneity of preferences across the population. There was an unmet demand for accessible, medium-density housing, with some households willing to trade off dwelling size and neighbourhood type for higher accessibility or lower prices. The study also found that more people currently drive than would prefer to, with long journey times, safety concerns, unreliable services, and a lack of infrastructure acting as barriers to active and public transport. Households preferring low density are more likely to occupy their preferred dwelling type and be able to use their preferred transport mode. In contrast, those preferring high accessibility or driven by price are more likely to experience a mismatch between their preferred and current dwelling type, and are less likely to be able to use their preferred transport mode.</p>

Identifying Dietary Consumption Patterns from Survey Data: a Bayesian Nonparametric Latent Class Model

Dietary intake is one of the largest contributing factors to cardiovascular health in the United States. Amongst low-income adults, the impact is even more devastating.Dietary assessments, such as 24-hour recalls, provide snapshots of dietary habits in a study population. Questions remain on how generalizable those snapshots are in nationally representative survey data, where certain subgroups are sampled disproportionately to comprehensively examine the population. Many of the models that derive dietary patterns account for study design by incorporating the sampling weights to the derived model parameter estimates post hoc. We propose a Bayesian overfitted latent class model that accounts for survey design and sampling variability to derive dietary patterns in adults aged 20 and older. We compare these results with a subset of the population, adults considered low-income (at or below the 130% poverty income threshold) to understand if and how these patterns generalize in a smaller subpopulation. Using dietary intake data from the National Health and Nutrition Examination Surveys, we identified six dietary patterns in the US adult population. These differed in consumption features found in the five dietary patterns derived in low-income adults. Reproducible code/data are provided on GitHub to encourage further research and application in this area.

Resource Efficiency and Circular Economy in European SMEs: Investigating the Role of Green Jobs and Skills

This study explored the size and potential of green employment for circular economy (CE) in small and medium enterprises (SMEs) in the European Union, and investigated the role of green jobs and skills for the implementation of CE practices. The data were collected in a Eurobarometer survey, and refer to resource efficiency, green markets, and CE procedures. Lack of environmental expertise is one of the factors that might be perceived as an obstacle when trying to implement resource-efficiency actions. Previous research has shown that, although resource-efficiency practices are adopted by firms in all European countries, there are differences both within and between countries. The analysis of the determinants of green behavior by European SMEs was completed by a study of heterogeneity across firms and within countries with a multilevel latent class model, a hierarchical clustering method. A general important observation is that having no workers dedicated to green jobs is strongly correlated to the probability of adopting resource-efficiency practices, while perceiving the need of extra environmental skills has a positive effect on the intention to implement actions in the future. Other characteristics of the firms play a significant impact on resource efficiency: in general, older and bigger firms, with larger yearly turnover, are more prone to implement actions.

Accuracy of computer-aided chest X-ray screening in the Kenya National Tuberculosis Prevalence Survey

Background: Community–based screening for tuberculosis (TB) could improve detection but is resource intensive. We set out to evaluate the accuracy of computer–aided TB screening using digital chest X-ray (CXR) to determine if this approach met target product profiles (TPP) for community–based screening. Methods: CXR images from participants in the 2016 Kenya National TB Prevalence Survey were evaluated using CAD4TBv6 (Delft Imaging), giving a probabilistic score for pulmonary TB ranging from 0 (low probability) to 99 (high probability). We constructed a Bayesian latent class model to estimate the accuracy of CAD4TBv6 screening compared to bacteriologically–confirmed TB across CAD4TBv6 threshold cut–offs, incorporating data on Clinical Officer CXR interpretation, participant demographics (age, sex, TB symptoms, previous TB history), and sputum results. We compared model–estimated sensitivity and specificity of CAD4TBv6 to optimum and minimum TPPs. Results: Of 63,050 prevalence survey participants, 61,848 (98%) had analysable CXR images, and 8,966 (14.5%) underwent sputum bacteriological testing; 298 had bacteriologically–confirmed pulmonary TB. Median CAD4TBv6 scores for participants with bacteriologically–confirmed TB were significantly higher (72, IQR: 58–82.75) compared to participants with bacteriologically–negative sputum results (49, IQR: 44–57, p<0.0001). CAD4TBv6 met the optimum TPP; with the threshold set to achieve a mean sensitivity of 95% (optimum TPP), specificity was 83.3%, (95% credible interval [CrI]: 83.0%–83.7%, CAD4TBv6 threshold: 55). There was considerable variation in accuracy by participant characteristics, with older individuals and those with previous TB having lowest specificity. Conclusions: CAD4TBv6 met the optimal TPP for TB community screening. To optimise screening accuracy and efficiency of confirmatory sputum testing, we recommend that an adaptive approach to threshold setting is adopted based on participant characteristics.

Anti-spike antibody response to natural SARS-CoV-2 infection in the general population

Understanding the trajectory, duration, and determinants of antibody responses after SARS-CoV-2 infection can inform subsequent protection and risk of reinfection, however large-scale representative studies are limited. Here we estimated antibody response after SARS-CoV-2 infection in the general population using representative data from 7,256 United Kingdom COVID-19 infection survey participants who had positive swab SARS-CoV-2 PCR tests from 26-April-2020 to 14-June-2021. A latent class model classified 24% of participants as ‘non-responders’ not developing anti-spike antibodies, who were older, had higher SARS-CoV-2 cycle threshold values during infection (i.e. lower viral burden), and less frequently reported any symptoms. Among those who seroconverted, using Bayesian linear mixed models, the estimated anti-spike IgG peak level was 7.3-fold higher than the level previously associated with 50% protection against reinfection, with higher peak levels in older participants and those of non-white ethnicity. The estimated anti-spike IgG half-life was 184 days, being longer in females and those of white ethnicity. We estimated antibody levels associated with protection against reinfection likely last 1.5-2 years on average, with levels associated with protection from severe infection present for several years. These estimates could inform planning for vaccination booster strategies.