Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period. Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport. Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements. It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations.

This dissertation studies social incentives in pro-social behavior and its various implications, including but not limited to disclosure policies, fundraising strategies and geographic polarization. / Economics

This thesis focuses on the design of field experiments with blocks to study treatment effects for a number of treatments. Small field plots are available but located in several blocks and each plot is assigned to a treatment in the experiment. Due to spatial correlation among the plots, the allocation of the treatments to plots has influence on the analysis of the treatment effects. When the spatial correlation is known, optimal allocations (designs) of the treatments to plots have been studied in the literature. However, the spatial correlation is usually unknown in practice, so we propose a robust criterion to study optimal designs of the treatments to plots. Neighbourhoods of correlation structures are introduced and a modified generalized least squares estimator is discussed. A simulated annealing algorithm is implemented to compute optimal/robust designs. Various results are obtained for different experimental settings. Some theoretical results are also proved in the thesis. / Graduate

This dissertation explores what factors and institutions influence individual decision making and their economic impacts on the society, using approaches of laboratory and field experiments. The first essay addresses the effect of communication on cooperation. The second essay explores various types of public recognition, and their impacts on individual donation. The third essay studies how principals use their time in K-12 schools and the potential impact on student and school outcomes. The first essay employs a laboratory experiment including three factors in human interactions, a noisy environment, indefinite length of interactions, and various levels of communication, to study what factors make individuals more cooperative. Results show that subjects are less cooperative in a noisy environment, and communication via fixed messages is not a remedy for the low cooperation rate in this noisy environment. However, communication via free messages leads to more cooperations, and it maintains cooperation rate at a high level over time. The second essay is a joint work with Yefeng Chen, Haoran He, and Jun Luo. We conduct a field experiment to investigate how public recognition influences individual charitable giving. We design five treatments with distinct public recognition schemes and vary the timing when we offer opportunities of public recognition. Results show that both donation amount and participation rate are significantly higher when we mandate recognition. However, public recognition offered before donation crowds out small donations and thus lowers the participation rate. We claim that public recognition is a “double-edged sword” on individual charitable giving. The third essay is a joint work with Mary Mira. We conduct a principal motion study in Fulton County, Georgia and shadow 30 school principals from all levels of public K-12 schools for two work days. We link our observational data with student performance data from state-wide standard scores. Results show that principals’ time spend on building and maintaining school culture and school climate, as well as evaluating teachers and school staff are most positively related to student performance.

A relação entre preço e posicionamento de produto nas prateleiras de varejo ainda tem espaço para descobertas na literatura de marketing. O objetivo central dessa dissertação foi identificar o efeito do posicionamento de produtos levando em consideração o seu preço e a escolha do consumidor; mais especificamente o efeito positivo do posicionamento lógico de preços (i.e produtos posicionados do menor ao maior preço nas prateleiras) na escolha final, facilidade de escolha e número de unidades vendidas. Dois estudos foram feitos em busca de resultados, o primeiro sendo um experimento online, no qual escolha e facilidade de escolha foram estudadas a partir do posicionamento de preço. O segundo estudo foi um experimento de campo, no qual unidades vendidas foram verificadas através do posicionamento de preço. Os resultados encontrados em ambos os estudos indicam que o posicionamento de produtos a partir de uma ordem lógica de preço afeta a escolha do consumidor, embora não através da facilidade de escolha, e, mais ainda, afeta positivamente a quantidade de produtos vendidos. Contudo, verificou-se que o posicionamento a partir de preço não tem como consequência a facilidade de escolha. / The relationship between price and product positioning on retail shelves still has room for breakthroughs in marketing literature. The main goal of this dissertation was to identify the effect of product placement, taking into account its price, and consumer choice; more specifically, the positive effect of product placement by a logical positioning of prices (i.e. products positioned from the lowest to the highest price on the shelves) on the final choice, choice easiness and overall number of units sold. Two studies were conducted to search for these results, the first one as an online experiment, which studied choice and choice easiness from price positioning. In this first study was found that there is a positive relation between logical price arrangement (i.e. positioning products from the cheapest to the most expensive one) and consumer choice. However, price positioning does not significantly affect the ease of choice. The second study was a field experiment, in which the overall number of units sold was verified through price positioning. The results found in both studies indicate that the positioning of products from a logical price order affects consumer choice, though not through easiness of choice and, moreover, positively affects the quantity of products sold. Yet, it has been found that considering primily price to choose a shelf position does not have as consequence easiness of choice.

abstract: Total digital media advertising spending of $72.5 billion surpassed total television Ad spending of $71.3 billion for the first time ever in 2016. Approximately $39 billion, or 54% of the digital media advertising spend, involved pre-programmed software that purchased Ads on behalf of a buyer in Real-Time Bidding (RTB) settings. A major concern for Ad buyers is sub-optimal spending in RTB settings owing to biases in the attribution of customer conversions to Ad impressions. The purpose of this research is twofold. First, identify and propose a novel experimental design and analysis plan for to handling a previously unidentified and unaddressed source of endogeneity: count/quality simultaneity bias (CQB). Second, conduct a field study using data for Ad response rates, cost, and observed consumer behavior to solve for the profit maximizing daily Ad frequency per customer. One large online retailer provided data for Ad impressions, bid costs, response rates, revenue per visit, and operating costs for 153,561 unique users over 23 days. Unique visitors were randomly assigned to one of seven treatment groups with one, two, three, four, five, and six impressions per day limits as well as a final condition with no daily impression cap. Ordinary least square models (OLS) were fit to the data and a non-linear relationship between Ad impressions and site visits demonstrating declining marginal effect of Ad impression on site visits after an optimal point. The results of the field study confirmed the existence of negative CQB and demonstrated how my novel experimental design and analysis can reduce the negative bias in the estimate of impression quantity on customer response. Second, managers interested in improving the efficiency of advertising spend should restrict display advertising to only the highest quality inventory through specific site targeting and by leveraging direct buys and private marketplace deals. This strategy ensures that subsequent impressions are not of lower quality by restricting the pool of possible impressions from a homogenous set of high quality inventory. / Dissertation/Thesis / Doctoral Dissertation Business Administration 2017

A relação entre preço e posicionamento de produto nas prateleiras de varejo ainda tem espaço para descobertas na literatura de marketing. O objetivo central dessa dissertação foi identificar o efeito do posicionamento de produtos levando em consideração o seu preço e a escolha do consumidor; mais especificamente o efeito positivo do posicionamento lógico de preços (i.e produtos posicionados do menor ao maior preço nas prateleiras) na escolha final, facilidade de escolha e número de unidades vendidas. Dois estudos foram feitos em busca de resultados, o primeiro sendo um experimento online, no qual escolha e facilidade de escolha foram estudadas a partir do posicionamento de preço. O segundo estudo foi um experimento de campo, no qual unidades vendidas foram verificadas através do posicionamento de preço. Os resultados encontrados em ambos os estudos indicam que o posicionamento de produtos a partir de uma ordem lógica de preço afeta a escolha do consumidor, embora não através da facilidade de escolha, e, mais ainda, afeta positivamente a quantidade de produtos vendidos. Contudo, verificou-se que o posicionamento a partir de preço não tem como consequência a facilidade de escolha. / The relationship between price and product positioning on retail shelves still has room for breakthroughs in marketing literature. The main goal of this dissertation was to identify the effect of product placement, taking into account its price, and consumer choice; more specifically, the positive effect of product placement by a logical positioning of prices (i.e. products positioned from the lowest to the highest price on the shelves) on the final choice, choice easiness and overall number of units sold. Two studies were conducted to search for these results, the first one as an online experiment, which studied choice and choice easiness from price positioning. In this first study was found that there is a positive relation between logical price arrangement (i.e. positioning products from the cheapest to the most expensive one) and consumer choice. However, price positioning does not significantly affect the ease of choice. The second study was a field experiment, in which the overall number of units sold was verified through price positioning. The results found in both studies indicate that the positioning of products from a logical price order affects consumer choice, though not through easiness of choice and, moreover, positively affects the quantity of products sold. Yet, it has been found that considering primily price to choose a shelf position does not have as consequence easiness of choice.

We examined effects of the macroalgae Laurencia and Palisada spp. on epifauna within seagrass beds of Thalassia testudinum. First we conducted a field survey of Thalassia testudinum beds with varying densities of Laurencia and Palisada spp. Second, we conducted a field experiment, manipulating natural and simulated Laurencia and Palisada spp. In the field survey, we found that total faunal biomass (g m-2) increased significantly with Laurencia and Palisada spp. cover. In the experiment, natural Laurencia and Palisada spp. supported an increased density (No. m-2) of fauna, however, faunal values were highest in the simulated algae treatment. This suggests that the mechanism of increased density/biomass due to Laurencia and Palisada spp. is structural complexity. Since habitat quality in Thalassia testudinum beds may be mediated by associated macroalgae, these small-scale habitat factors need to be incorporated in habitat and ecosystem conservation plans.

This dissertation comprises three essays that examine critical aspects of fiscal policy and explores important determinants of tax compliance in a developing country context. The first essay examines the fiscal response to changes in debt-to-GDP for a panel of developing countries. Our empirical strategy adopts a dynamic difference generalized methods of moments (DGMM) model with forward orthogonal deviation. We find a positive and significant response for the primary balance and ‘fiscal effort’ to changes in debt-to-GDP. For the fiscal components, we find a positive relationship between debt-to-GDP and general and tax revenues, and a negative relationship with primary spending. We also find evidence of nonlinearities, with countries making larger increases in the primary balance and fiscal effort at higher levels of debt, largely driven by increases in revenues. Higher income countries demonstrate a greater propensity to adjust along the revenue margins, compared to lower income countries. This might be indicative of systemic revenue mobilization challenges facing the latter. The second essay examines the effect of the provision of taxpayer services on filing and payment of the corporate income tax (CIT) and general consumption tax (GCT) for large taxpayers in Jamaica. We use a regression discontinuity design (RDD) that exploits an exogenous jump in the intensity of taxpayer service delivery, which occurs when a taxpayer reaches gross receipts of J$500 million (US$5.7 million) and is selected into the large taxpayer office (LTO). The results indicate null effects for the CIT but positive filing and payment compliance effects for the GCT. The contrasting results for the CIT and GCT may be due to the relatively weaker legal enforcement framework of the former. The results provide suggestive evidence of a complementarity between the strength of the legal enforcement framework of the taxing regime and the provision of taxpayer services. In the third essay we implement public goods messaging experiments to examine the effects on personal income tax (PIT) compliance among self-employed individuals in Jamaica. In the first sub-experiment we examine the effect of the standard public goods message on payment of quarterly PIT obligations. In the second sub-experiment we focus on payment of PIT arrears and expand the message context to include a variant of the standard public goods message – which provides additional information on actual spending on key public goods and services. The compliance outcomes in sub-experiment two relate to established PIT delinquencies, compared to sub-experiment one where there is no legal obligation to comply. We find that the standard public goods message had no effect on compliance with quarterly PIT payments in sub-experiment one. However results from sub-experiment two indicate positive compliance effects from the standard and augmented public goods messages on the probability of making a payment and the amount of PIT arrears paid after nineteen weeks. Point estimates from the standard and augmented public goods messages are not statistically different for any of the outcomes examined; suggesting that additional information on public spending allocations does not matter.

Lo studio presenta un analisi dettagliata sul comportamento dei giocatori d'azzardo. I dati sono stati raccolti tramite un esperimento condotto “sul campo” che ha osservato i giocatori durante la loro attività di gioco in un agenzia di scommesse. L'esperimento ha permesso di ottenere il grado di severità del disordine da gioco d’azzardo e i principali tratti comportamentali dei partecipanti. La misurazione di tali tratti ha permesso di comprendere quali tra questi, meglio prediceva l’insorgere del disordine da gioco d’azzardo. La seconda parte del lavoro è stata rivolta a studiare la possibile relazione causale tra attività di gioco e una possibile modifica dei tratti comportamentali. Inoltre la diretta osservazione dei giocatori durante l’attività di gioco ha permesso di avere una traccia dettagliata del loro comportamento di gioco. I risultati sottolineano importanti differenze tra i comportamenti dei giocatori osservati usando procedure sperimentali e i comportamenti osservati durante l’attività di gioco. Nel primo caso non è stato rilevato nessun impatto significativo sulle preferenze individuali dovuto all’attività di gioco. Nel secondo caso, invece, si trova conferma del fenomeno conosciuto come “diminishing sensitivity”. In altre parole, all’aumentare delle perdite subite durante l’attività di gioco aumenta la propensione al rischio dei giocatori. / The thesis presents a lab-in-the-field experiment collecting data on gamblers’ behaviour. The study provides an estimate of the incidence of Problematic Gambling (PG) among the usual customers of a large betting agency in Milan. We elicit in an incentivized manner a large battery of behavioural traits in order to investigate which of them are mostly characterizing PG. Moreover, we investigate a causal relationship between gambling activity and behavioural traits. We also keep detailed track of the gambling activity during the day of the interview to see which are the more interest patterns of the gambling activity. The results underline important differences between real and experimental observation. When we use experimental task to investigate a possible variation in risk preferences due to gambling activity we do not observe any significant impact on risk preferences. When we inspect risk preferences using data coming from the real gambling activity we find evidence of the diminishing sensitivity phenomenon. The more losses they have collected during gambling, the more is the risk that gamblers are likely to take in the subsequent bets. These results indicate that gamblers are not risk-seekers in general, but their risk propensity seems to rise when they are involved in gambling.