Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

A method is presented of acquiring the principles of three sorting algorithms through developing interactive applications in Excel.

<p>Geographic clustering has been linked to contemporary political polarization by jour- nalists and other researchers in recent years, most recently and notably by Bishop and Cushing (2008). In these accounts, clustering is motivated, in part, by shared tastes for combinations of place attributes that attract individuals with interrelated values and similar characteristics or skillsets. In order to test whether political pref- erences aligns with location choice, this paper proposes a sorting model based on the composition of migrants' political preferences. </p><p>Sorting is defined as the increase in the variation of a parameter of preference distributions of different location, in the absence of individual preference change. The model estimates the separate prob- abilities of party identification in U.S. congressional districts among migrants and non-migrants.</p><p>Based on an empirical application using the 2006 Cooperative Congressional Elec- tion Study, I find that a significant number of district satisfy the sorting condition. Aa multinomial logit model predicts that individual ideology is significant explana- tory variable in the partisanship of destination districts among migrants, even after controlling for the partisanship of originating districts.</p><p>The final chapter evaluates sorting and polarization in U.S. congressional districts based on intra-decade changes to population size. I show that overall polarization in high growth districts exceeds sorting, and suggest this results from an increase in electoral bias that could result from heavy migration into districts that begin the decade as very homogenous.</p> / Dissertation

This dissertation analyzes the effect of smaller classes on student performance using student-level test score data from the state of Texas, focusing on three specific issues: heterogeneity in the returns to smaller classes across a score distribution of students, the relationship between class size and students' moving decisions, and the connection between smaller classes and schools' class division procedures. I first examine evidence of heterogeneity in the returns to class size reductions across a score distribution of students. I divide students into decile groups based on their previous year test scores, and I estimate the returns to smaller classes for each of the deciles. The empirical evidence supports the hypothesis that there are significant differences in students' responses to class size, based on their previous test scores. I then model the class size effect simultaneously with students' decisions to switch schools, which is important because movers compose a substantial fraction of the dataset, and because class size effects vary between movers and nonmovers. Recognizing that students move for different reasons, only some of which are school-related, I present a two-type moving model in which students are categorized as endogenous movers or exogenous movers. I estimate the model estimated using maximum likelihood. The results reveal key biases in traditional estimates of the moving effect and suggest significant differences in the class size effect across mover types. I also explore the class size effect in conjunction with schools' decisions to sort students into different classes. Using student-level data in which students are linked to specific classes, I disentangle the class size effect from the sorting effect. Including a variable indicating the sorting index of a school decreases the magnitude and significance of the class size effect. I also examine different types of sorting. The findings suggest that sorting students into more homogeneous groups is beneficial for both high and low scoring students.

published_or_final_version / abstract / Computer Science / Master / Master of Philosophy

This dissertation consists of three essays in applied microeconomics. The first chapter offers an overview of the work, highlighting the main contributions, methodology and results.The second chapter extensively discusses how one could and should take into account two different but inter-related impacts that tournament prizes have on outcome: the sorting and the incentive effects. The sorting effect refers to the fact that if higher prizes are offered in a tournament, more able participants will join. The incentive effect of prizes relates to an increase in effort corresponding to an increase in prizes, from participants that already decided to join a competition. Previous theoretical and empirical literature focused mainly on the second effect as if relevantly economic tournaments are close in nature. Also, previous empirical studies missed an important channel through which prizes affect outcome and likely estimated biased coefficients for the incentive effect.The third chapter analyzes the impact of the first old-age relief program on the health of the elderly in the United States in the 1930s. The study attempts to provide a picture of how the elderly would fare in an economy where the Social Security system of today does not exist but instead a less birocratic and costly system is in place. The 1930s offers an economist interested in such a counterfactual analysis a unique opportunity since this is precisely the time when Social Security had not started to make payments yet but the states and the federal government became involved in financially supporting the needy elderly.The fourth chapter examines whether public messages can break bubbles in experimental asset markets. This study has policy relevancy in terms of the role a central bank might have in targeting not only inflation as currently defined but asset prices as well. Whereas this role is controversial and remains to be determined, theoretical models advanced the idea of public messages as potential coordination devices among traders in an environment that experiences a bubble. Chapter 4 details the design and results of an experiment that tests this coordination role of a public message.The final chapter summarizes the findings.

Children at a certain age often have difficulty in flexibly shifting attention between different representational schemes. One example of such cognitive inflexibility occurs in the Dimensional Change Card Sorting (DCCS) task in which 3-year-old children have difficulty switching between sorting dimensions. For instance, after initially sorting the cards by one dimension (e.g., colour) they are unable to sort the cards by a second dimension (e.g., shape). This finding has been primarily associated with problems in attention or inhibition. The present study investigated the role of perceptual information on children’s dimensional shift abilities by manipulating the perceptual characteristics of both task-relevant (the colour or shape of the images on the cards) and task-irrelevant (the background colour or shape of the actual cards themselves) aspects of the task materials between the pre- and post-switch experimental phases. Across three experiments better performance was observed when either task-relevant or task-irrelevant information was changed, with this improved performance occurring when these changes were salient enough to induce a stimulus novelty effect. Experiment 4 investigated yet another perceptual feature of the task; the degree of stimulus realism (abstractness) on children’s cognitive flexibility. Children successfully sorted the cards when three-dimensional stimuli were used but perseverated when using two-dimensional cards, providing evidence for the role of representational status of the stimuli in influencing children’s dimensional switching. Manipulations made to increase the salience of the task material as well as those resulting in reduction of similarity between the two phases of the tasks (or increased novelty) were used to enhance children’s cognitive flexibility. Overall, these findings highlight the critical role played by the perceptual information of the overall experimental context, and have important implications for theories of cognitive flexibility.

Understanding the mechanisms plants utilize for seed storage protein (SSP) synthesis, transport and deposition have the potential rewards of enabling high yields of modified or foreign proteins. Hayashi et al. (1999) indicated that the machinery devoted to the synthesis of protein storage vacuoles in cotyledon cells can be induced in vegetative tissue by the constitutive expression of a pumpkin 2S albumin phosphinothricin-acetyl-transferase gene fusion (pumpkin 2S-PAT) resulting in the biogenesis of precursor-accumulating (PAC) vesicles in Arabidopsis leaves. This discovery was the impetus behind the work described which sought to examine this phenomenon further by ectopically evoking SSP trafficking and vesicle biogenesis machinery in leaves. With the aim of elucidating the mechanisms necessary to evoke PAC vesicle biogenesis, a suite of constructs including the pumpkin 2S-PAT and analogous napin-PAT and napin-GFP variants were synthesized. Analysis of these transgenes in Arabidopsis revealed that the pumpkin 2S albumin has a capacity unique from napin peptides to result in fusion protein accumulation. Further, the truncated pumpkin 2S albumin peptide and the pumpkin 2S albumin C-terminus were found to direct deposition to vesicles; however, the C-terminus alone was not enough to direct deposition to vesicles unless combined with a significantly shortened napin peptide. An increased ER protein throughput was correlated to trafficking of the fusion protein by Golgi-independent mechanisms resulting in stable accumulation of the unprocessed protein whereas less ER throughput indicated passage through the Golgi-dependent pathway resulting in accumulation of a processed variant. At the level of gene expression, as examined by a microarray study, both inducible and constitutive ectopic expression of pumpkin 2S-PAT resulted in substantial perturbations of the endomembrane system affecting protein folding, flowering time and ER-associated biosynthetic functions which indicated that modulation of flowering time and photoperiodism are highly dependent on protein trafficking and vacuolar biogenesis mechanisms and that high ER protein throughput occurs at the expense of biosynthesis and cessation of ER functioning.

The purpose of this study was to examine attitudes and potential for sorting of food waste at restaurants in the central part of Umeå. The information was gathered through a questionnaire survey and by exploring different sorting methods. The questionnaire was sent to 55 restaurants and 24 of them responded. A majority of the respondents wanted to sort out food waste. 72.8 % believe they have a good or moderate potential to sort out food waste in the future and none of the respondents answered that they believed that they had no means of sorting out food waste. Overall, the restaurants are considered to have good attitudes about sorting food waste. However, this may be because the respondents have a better attitude than those who chose not to respond. The sorting methods were evaluated by reviewing reports written by government agencies and industry associations. Mill systems connected to a tank had the most pros and least cons of the sorting methods, but were expensive to install and required a lot of space. Sorting in individual containers was less expensive and required less space but was considered worse from a working environment standpoint. It seems that a combination of individual containers and a mill system connected to a tank suit most restaurants.

Children at a certain age often have difficulty in flexibly shifting attention between different representational schemes. One example of such cognitive inflexibility occurs in the Dimensional Change Card Sorting (DCCS) task in which 3-year-old children have difficulty switching between sorting dimensions. For instance, after initially sorting the cards by one dimension (e.g., colour) they are unable to sort the cards by a second dimension (e.g., shape). This finding has been primarily associated with problems in attention or inhibition. The present study investigated the role of perceptual information on children’s dimensional shift abilities by manipulating the perceptual characteristics of both task-relevant (the colour or shape of the images on the cards) and task-irrelevant (the background colour or shape of the actual cards themselves) aspects of the task materials between the pre- and post-switch experimental phases. Across three experiments better performance was observed when either task-relevant or task-irrelevant information was changed, with this improved performance occurring when these changes were salient enough to induce a stimulus novelty effect. Experiment 4 investigated yet another perceptual feature of the task; the degree of stimulus realism (abstractness) on children’s cognitive flexibility. Children successfully sorted the cards when three-dimensional stimuli were used but perseverated when using two-dimensional cards, providing evidence for the role of representational status of the stimuli in influencing children’s dimensional switching. Manipulations made to increase the salience of the task material as well as those resulting in reduction of similarity between the two phases of the tasks (or increased novelty) were used to enhance children’s cognitive flexibility. Overall, these findings highlight the critical role played by the perceptual information of the overall experimental context, and have important implications for theories of cognitive flexibility.