Doctor of Philosophy / Department of Agricultural Economics / Jason S. Bergtold / The adoption of new technologies on-farm is affected by socio-economic, risk management behavior, and market factors. The adoption of cellulosic biofuel feedstock enterprises and conservation practices plays an important role in the future of Kansas agriculture. No set markets currently exist for bioenergy feedstocks and farmers may be reluctant to produce the feedstocks without contracts to mitigate uncertainty and risk. Adoption of conservation practices to improve soil productivity and health may be affected by risk considerations also. The purpose of this dissertation is to study how market mechanisms and risk influence Kansas farmers’ willingness to adopt cellulosic biofuel feedstock enterprises and conservation practices on-farm. The first essay examines farmers’ willingness to grow switchgrass under contract using a stated choice approach. Data were collected using an enumerated survey of Kansas farmers and analyzed using latent class logistic regression models. Farmers whose primary enterprise is livestock are less inclined to grow switchgrass. In addition, shorter contracts, greater harvest flexibility, crop insurance, and cost-share assistance increase the likelihood farmers will grow switchgrass. The second essay examines how farmers’ risk perceptions impact conservation practice adoption. Factor analysis of survey data was used to identify primary risk management behaviors of Kansas farmers. A multinomial logit model of conservation practice adoption incorporating these risk behaviors was developed. Estimation results indicate that different risk management factors may have no significant impact on practice adoption. Farmers may not consider certain aspects of risk significant in their adoption decision. The third essay examines the effect of different risk management behaviors on farmers’ willingness to produce alternative cellulosic bioenergy feedstocks under contract. Data were collected using a farmer survey with a set of stated choice experiments and analyzed using factor analysis and latent class logistic regression models. While farmers approach risk management differently, the risk management behaviors identified have no significant impact on farmers’ willingness to produce corn stover and switchgrass but have a negative impact on farmers’ willingness to produce sweet sorghum as a biofuel feedstock. These results may indicate that farmers are indifferent toward adopting new bioenergy cropping enterprises when traditional crop production is profitable and more certain.

Piecewise latent class growth analysis (LCGA) was used to examine growth patterns in reading comprehension and passage reading fluency on easyCBM, a popular formative assessment system. Unlike conventional growth modeling, LCGA takes into account the heterogeneity of growth and may provide reliable predictions for later development. Because current methods for classifying students are still questionable, this modeling technique could be a viable alternative classification method to identifying students at risk for reading difficulty. Results from this study suggested heterogeneity in reading development. The latent classes and growth trajectories from the LCGA models were found to align closely with easyCBM's risk rating system. However, results from one school district did not fully generalize across another. The implications for future research on examining growth in reading are discussed.

The eCommerce industry introduced new business principles, as well as new strategies for achieving these principles, and as a result some traditional measures of success are no longer valid. We classified and ranked the performance of twenty business-to-consumer eCommerce companies by developing critical benchmarks using the Balanced scorecard methodology. We applied a Latent class model, a statistical model along the Bayesian framework, to facilitate the determination of the best and worst performing companies. An eCommerce site's greatest asset is its customers, which is why some of the most valued and sophisticated metrics used today evolve around customer behavior. The results from our classification and ranking procedure showed that companies that ranked high overall also ranked comparatively well in the customer analysis ranking, For example, Amazon.com, one of the highest rated eCommerce companies with a large customer base ranked second in the critical benchmark developed towards measuring customer analysis. The results from our simulation also showed that the Latent class model is a good fit for the classification procedure, and it has a high classification rate for the worst and best performing companies. The resulting work offers a practical tool with the ability to identify profitable investment opportunities for financial managers and analysts.

Physical activity (PA) has been labelled the miracle drug (Pimlott, 2010) and participating in regular PA has ample physical and mental wellbeing benefits. However, physical inactivity remains a critical public health concern, particularly across adolescence. In England the proportion of adolescents aged 13-15 years meeting the recommended guidelines for PA decreased significantly from those at a younger age (Health and Social Care Information Centre, 2009; 2012; 2015). The adolescent years (13 18 years) have been identified as the age of greatest decline in PA, although it is possible that large declines can also be seen at younger ages (Sallis, 2000). Among girls the decline in PA is greater at younger ages (9 12 years old) and among boys it is greater at older ages (13 16 years old) (Dumith, Gigante, Domingues, & Kohl, 2011). Thus, examining behaviour of early adolescents (aged 11-13 years) is a primary focus of this thesis. Researchers have called for a more comprehensive grasp of PA correlates and determinants and their impact on behaviour (Biddle & Mutrie, 2001, 2008). This broader picture needs to incorporate longitudinal study designs to accurately portray developmental changes (Evenson & Mota, 2011). This thesis aims to work towards a better understanding of associations among variables across aspects of the ecological model in relation to PA behaviour during early adolescence. Early adolescents within their first year of secondary school (year 7, aged 11 12 years) were recruited through schools across the East Midlands, United Kingdom (UK). These participants completed various measures across an 18 month period to compile all data required for the thesis. The thesis begins with a focus on active transport as a means of commuting to school which can significantly contribute to overall PA levels (Aibar, Bois, Generelo, Bengoechea, & Paillard, 2015; Slingerland, Borghouts, & Hesselink, 2012). The distance from home to school is an important influence on the decision to use active transport; however, ecological perspectives would suggest this variable may interact with individual, interpersonal and environmental factors. Therefore, the first study of this thesis investigates whether the relationship between distance to school and active transport is moderated by (i) gender, (ii) biological maturation, (iii) perceived family support for PA and (iv) multiple deprivation. Cross-sectional results from the baseline data collected demonstrated that the relationship between distance to school and the likelihood to actively travel to school is moderated by biological maturation, multiple deprivation and family support of PA in adolescents. Further analysis revealed that late-maturing children, those from less socio-economically deprived backgrounds and children with low family support of PA are less likely to actively commute to school as distance to school increases. Due to the interaction between these variables described above, the second study focused on the variables collectively using a person-oriented approach, which aimed to classify distinct profiles of early adolescents based on correlates of PA. The outcome variables were also broadened to include active transport and overall PA across two time points. Findings from this second study illustrate that the highly supported, shortest commuters produced the highest levels of self-reported PA and that affluent, short commuters were the most likely to use active transport to travel to school. The affluent, short commuters lived a relatively short distance to school in areas of the lowest deprivation and had relative moderate family support of PA. The highly supported, shortest commuters were characterised by the highest family support of PA and lived the shortest distance to school in areas of low deprivation. Study 1 evidenced an association between biological maturation and PA behaviour; however, study 2 displayed that biological maturation did not meaningfully contribute to the class characteristics, and were not a predictor of PA. Previous evidence as to whether early, average or late maturing adolescents are more likely to disengage from PA is mixed and tends to focus on one gender only (Sherar, Cumming, Eisenmann, Baxter-Jones, & Malina 2010; Bacil, Mazzardo, Rech, Legnani, & Campos, 2015). Thus for the third study a more focused inspection of biological maturity was undertaken. Biological maturity status was investigated as a predictor of PA behaviour at two subsequent time points (6 9 months after baseline and 12 18 months after baseline) and whether there was variation across genders. Findings displayed that biological maturity status does not predict subsequent PA, with no distinction across genders. To conclude, the final study examined additional forms of PA behaviour. For children to develop and maintain healthy PA behaviours, their PA during the school day, particularly during physical education (P.E) classes is important (Owen, Smith, Lubans, Ng, & Lonsdale, 2014). Self-reported PA was divided into school-time PA (during P.E. lessons, break and lunchtimes) and leisure-time PA (after school, during evenings and weekends). The final study fully utilised the longitudinal data collected and utilised longitudinal growth modelling to describe the changes in PA behaviour across 12-18 months during early adolescence. Results displayed that school-time PA and leisure-time PA are distinct. Males; those from less deprived backgrounds and individuals with higher family support of PA all separately reported more school-time PA than their counterparts (females, those from higher deprived backgrounds and individuals with lower family support of PA) at baseline. Males and those with higher family support of PA also reported more leisure-time PA than their respective counterparts at baseline. On average, both genders decreased in school-time PA across 18 months yet for leisure-time PA, on average, there was no change over time and no significant difference in the rate of change between genders. There were no observed significant differences in the rate of change between multiple deprivation status and biological maturation across the 18 months for both behaviours. For family support, on average school-time PA decreased over time and results showed significant difference in the rate of change between individuals with lower or higher levels of family support of PA across the 18 months. On average, there was no change over time for leisure-time PA yet there was a significant difference in the rate of change between individuals and their family support of PA across 18 months. Further analysis demonstrated if an individual s family support increases, so does their leisure-time PA and vice versa. These overall key findings demonstrate the complexity of PA behaviour throughout early adolescence. This thesis works towards predicting individuals, correlates and determinants that may be susceptible to physical inactivity and/or a decrease in activity over time. Results can be used to target and direct PA intervention work.

Previous research on marital help-seeking has often focused on formal approaches such as marital therapy or relationship education and there is a greater need to understand married individual's informal help-seeking behaviors. This study explores both formal and informal help-seeking behavior using a national sample of 745 participants who have thought about divorce within the past 6-months. Findings indicate these participants more often engaged in informal help-seeking approaches to repair their marriage. Of those sampled, only 25% engaged in marital therapy together and only 9% engaged in a marriage strengthening class while over 30% read a relationship themed self-help book or visited a website as a form of repair-behavior. A series of logistic regressions indicate there are no statistically significant differences in help-seeking behavior by gender while those that were highly religious and had more serious thoughts of divorce were more likely to engage in all forms of help-seeking. A latent class analysis was conducted to determine if there are common patterns in help-seeking behavior. Results indicate there are 4 distinct types of help-seekers: Highly Engaged (5%), Private Information Gatherers (7%), Private Seekers (43%), and Minimally Engaged (45%). Follow up analyses indicate having higher levels of religiosity or having more serious thoughts of divorce were both associated with a greater likelihood of being in one of the three more engaged classes compared to the minimally engaged class. Results demonstrate the need to place more emphasis on informal help-seeking approaches, private repair-behaviors, and to consider common patterns in help-seeking behavior.

Latent Class Analysis was used to explore different subgroups of individuals based on identity processes (using the DIDS) and protestant fundamentalism. Results indicate that a 6-group solution provided the best fit for our data. The six groups differed in terms of identity process variables (especially exploration in breath, exploration in depth, and identification with commitment), but only modestly in terms of fundamentalism.

The purpose of this dissertation was to expand the understanding of youth in psychiatric residential treatment facilities by using psychosocial indicators to develop subgroup profiles. Additionally, differences in treatment outcomes between subgroups and the extent to which within-treatment factors accounted for observed differences in treatment outcomes between subgroups were examined. Data were extracted from the case records of 447 youth who were served in psychiatric residential treatment facilities over a seven year span of time. A latent class analysis was used to identify and describe subgroups. A series of multivariate regression analyses were used to examine group differences in functional impairment at discharge. Next, a path analysis was used to determine if there were differences in average change in functional impairment from admission to discharge between subgroups and to test within treatment factors as potential mediators of group differences. Finally, a logistic regression was used to determine if there were differences between groups in the probability of discharging to a community-based placement or discharging to another congregate care facility. The latent class analysis revealed four distinct subgroups of youth. The analyses of treatment outcomes revealed statistically significant differences in the level of functional impairment at discharge and average change in impairment between groups. Results from the path model of indirect effects supported that within treatment factors accounted for a statistically significant proportion of the observed difference in change between groups. No differences were found in discharge placement outcomes between groups. Implications for future research, practice and policies focused on youth in residential treatment are discussed.

潛在群體分析及對應分析是在探討多個類別變數間關係常用的兩種分析方法，因其運用之領域不同，解說之方式不一，以致過去常被認為是兩種不相關的分析方法，然而實際卻非如此。本研究之目的係就雙變數及多變數的情況，針對這兩種分析方法間之關係作詳細的探討，並說明其對等及不對等的時機。 / Latent class analysis and correspondence analysis are two well-known methods that can be used to study the relationship between categorical variables. Since the two were developed and applied in two different fields in the past, they were never thought to be related. In this study, we examine the relationship between the two in more details. We further point out the situations where they are equivalent, and where they are not.

Choice-Based Conjoint (CBC) models are often used for pricing decisions, especially when scanner data models cannot be applied. Up to date, it is unclear how Choice-Based Conjoint (CBC) models perform in terms of forecasting real-world shop data. In this contribution, we measure the performance of a Latent Class CBC model not by means of an experimental hold-out sample but via aggregate scanner data. We find that the CBC model does not accurately predict real-world market shares, thus leading to wrong pricing decisions. In order to improve its forecasting performance, we propose a correction scheme based on scanner data. Our empirical analysis shows that the hybrid method improves the performance measures considerably. (author's abstract) / Series: Report Series SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

<p>This study examines whether trajectories of multiple social role occupancy, measured by level and dynamics of spouse, parent, and worker roles, are associated with mortality and concurrent trajectories of depressive symptoms and self-rated health. I frame hypotheses with role strain, role enhancement, role context, stress process, and life course theories to examine both within-person changes over age and between-person predictors of health status.</p><p></p><p>I use data from the Americans' Changing Lives Study, a nationally representative accelerated cohort panel study of U.S. adults interviewed in 1986, 1989, 1994, and 2001/2 with mortality tracking through 2006. I use latent class analysis to estimate disaggregated trajectories of role occupancy, role strain, role satisfaction, depressive symptoms, and self-rated health across the adult life course. I then use multinomial and logistic regression analyses to examine associations between role trajectories and health outcomes.</p><p>I find that (1) there is significant heterogeneity in trajectories of role occupancy and characteristics across the adult life course; (2) higher levels of social role occupancy are associated with better depressive symptom and mortality outcomes; (3) lower levels of role strain and higher levels of role satisfaction are associated with better depressive symptom outcomes, and (4); the association between role occupancy and health is robust to the inclusion of role characteristics. Thus, I find support for the role enhancement hypothesis in that higher levels of role occupancy are associated with better health outcomes irrespective of reward and strain associated with those roles.</p> / Dissertation