Broad swaths of humanity have become richer, healthier, and better educated. More of the world’s poorest have access to affordable credit, enabling them to invest in a better future. But what are the consequences? Does greater wealth or greater access to credit make people happier or more fulfilled? This dissertation presents essays on the relationship between wealth and well-being, the welfare effects of both debt and debt relief, and the kinds of normative analysis that help to inform good public policy. The first essay, The Methodology of Normative Policy Analysis (joint with Richard Zeckhauser), concerns disagreements in policy analysis and discourse. It provides a simple taxonomy of disagreement, identifying distinct categories within both the positive and values domains of normative policy analysis. Using disagreements in climate policy to illustrate, it demonstrates how illuminating the structure of disagreement helps to clarify the way forward. It concludes by suggesting a structure for policy analysis that can facilitate assessment, comparison, and debate by laying bare the most likely sources of disagreement. The second essay, Wealth and Well-being, tests a fundamental prediction of economic theory: that greater wealth causes greater well-being. It uses a natural experiment to estimate the causal effect of income on subjective well-being. Among a population of indebted farmers in rural India, the marginal effect of income on life satisfaction is found to be positive. However, the source of income appears to exert an important and independent effect. In this study the source is agricultural debt relief, which features a positive marginal effect but also a countervailing negative effect (perhaps due to stigma). The third essay, Moral Hindrance, argues that the total cost of default borne by low-income borrowers, including social, psychological, and other sanctions, is likely to be excessive, giving rise to sub-optimal borrower risk-taking and excessive borrower effort. I call this the moral hindrance problem, to distinguish it from the moral hazard problem often presumed by economists. The essay argues that policy should promote competition among lenders, encourage broader use of collateral, and allow interest rates to rise as necessary to meet borrower demand for varying loan conditions.

Green buildings are increasingly in demand yet current green building practices often do not consider hazard mitigation. High-performance buildings that can withstand hazards, protect residents, and do not need to be rebuilt following a disaster are truly sustainable buildings. This report focuses on current hazard mitigation and disaster resilience standards for wildfires and earthquakes through an in-depth analysis of case studies and best practices for these hazards. The U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) framework is the ideal vehicle to incorporate hazard mitigation methods into official green building certification. Language for a new LEED Hazard Mitigation and Resilience credit area is established using guidelines for hazard mitigation for wildfires and earthquakes. / text

This study investigates evidence for linkages and fault interactions centred on the Cust Anticline in Northwest Canterbury between Starvation Hill to the southwest and the Ashley and Loburn faults to the northeast. An integrated programme of geologic, geomorphic, paleo-seismic and geophysical analyses was undertaken owing to a lack of surface exposures and difficulty in distinguishing active tectonic features from fluvial and/or aeolian features across the low-relief Canterbury Plains. LiDAR analysis identified surface expression of several previously unrecognised active fault traces across the low-relief aggradation surfaces of the Canterbury Plains. Their presence is consistent with predictions of a fault relay exploiting the structural mesh across the region. This is characterised by interactions of northeast-striking contractional faults and a series of re-activating inherited Late Cretaceous normal faults, the latter now functioning as E–W-striking dextral transpressive faults. LiDAR also allowed for detailed analysis of the surface expression of individual faults and folds across the Cust Anticline contractional restraining bend, which is evolving as a pop-up structure within the newly established dextral shear system that is exploiting the inherited, now re-activated, basement fault zone. Paleo-seismic trenches were located on the crest of the western arm of the Cust Anticline and across a previously unrecognised E–W-striking fault trace, immediately southwest of the steeply plunging Cust Anticline termination. These studies confirmed the location and structural style of north-northeast-striking faults and an E–W-striking fault associated with the development of this structural culmination. A review of available industry seismic reflection lines emphasised the presence of a series of common structural styles having the same underlying structural drivers but with varying degrees of development and expression, both in the seismic profiles and in surface elevations across the study area. Based on LiDAR surface mapping and preliminary re-analysis of industry seismic reflection data, four fault zones are identified across the restraining bend structural culminations, which together form the proposed Oxford–Cust–Ashley Fault System. The 2010–2012 Canterbury Earthquake Sequence showed many similarities to the structural pattern established across the Oxford–Cust–Ashley Fault System, emphasising the importance of identification and characterization of presently hidden fault sources, and the understanding of fault network linkages, in order to improve constraints on earthquake source potential. Improved understanding of potentially-interactive fault sources in Northwest Canterbury, with the potential for combined initial fault rupture and spatial and temporal rupture propagation across this fault system, can be used in probabilistic seismic hazard analysis for the region, which is essential for the suitability and sustainability of future social and economic development.

In a series of three studies, we assess modern debris-flow hazards in Arizona from extreme precipitation events and following wildfires. In the first study, we use a combination of surficial geologic mapping, ¹⁰Be exposure age dating and modeling to assess prehistoric to modern debris-flow deposits on two alluvial fans in order to place debris-flow hazards in the context of both the modern environment and the last major period of climate change. Late Pleistocene to early Holocene debris flows were larger and likely initiated by larger landslides or other mass movement failures, unlike recent debris flows that typically initiate from shallow (~1 m) failures and scour channels, thus limiting total volumes. In the second study we assess the predictive strengths of existing post wildfire debris-flow probability and volume models for use in Arizona's varied physiographic regions, and define a new rainfall threshold valid for Arizona. We show that all of the models have adequate predictive strength throughout most of the state, and that the debris-flow volume model over-predicts in all of our study areas. Our analysis shows that the choice of a model for a hazard assessment depends strongly on location. The objectively defined rainfall intensity-duration thresholds of I₁₀ and I₁₅ (52 and 42 mm h⁻¹, respectively) have the strongest predictive strengths, although all five of the threshold models performed well. In the third study, we explore various basin physiographic and soil burn severity factors to identify patterns and criteria that can be used to discriminate between potential non-debris-flow (nD) and debris-flow (D) producing basins. Findings from this study show that a metric of percent basins area with high soil burn severity on slopes ≥30 degrees provides a stronger discrimination between nD and D basins than do basin metrics, such as mean basin gradient or relief. Mean basin elevation was also found to discriminate nD from D basins and is likely a proxy for forest type and density, which relates to soil thickness, root density and the magnitude of post-disturbance erosion. Finally, we found that post-fire channel heads formed at essentially the same slope range (~30-40 degrees) as saturation-induced hill slope failures.

A probabilistic framework is developed to assess the structural reliability of offshore wind turbines. Probabilistic models are developed to predict the deformation, shear force and bending moment demands on the support structure of wind turbines. The proposed probabilistic models are developed starting from a commonly accepted deterministic model and by adding correction terms and model errors to capture respectively, the inherent bias and the uncertainty in developed models. A Bayesian approach is then used to assess the model parameters incorporating the information from virtual experiment data. The database of virtual experiments is generated using detailed three-dimensional finite element analyses of a suite of typical offshore wind turbines. The finite element analyses properly account for the nonlinear soil-structure interaction. Separate probabilistic demand models are developed for three operational/load conditions including: (1) operating under day-to-day wind and wave loading; (2) operating throughout earthquake in presence of day-to-day loads; and (3) parked under extreme wind speeds and earthquake ground motions. The proposed approach gives special attention to the treatment of both aleatory and epistemic uncertainties in predicting the demands on the support structure of wind turbines. The developed demand models are then used to assess the reliability of the support structure of wind turbines based on the proposed damage states for typical wind turbines and their corresponding performance levels. A multi-hazard fragility surface of a given wind turbine support structure as well as the seismic and wind hazards at a specific site location are incorporated into a probabilistic framework to estimate the annual probability of failure of the support structure. Finally, a framework is proposed to investigate the performance of offshore wind turbines operating under day-to-day loads based on their availability for power production. To this end, probabilistic models are proposed to predict the mean and standard deviation of drift response of the tower. The results are used in a random vibration based framework to assess the fragility as the probability of exceeding certain drift thresholds given specific levels of wind speed.

A critical part of traffic safety is a driver’s ability to detect and respond to emergency roadway hazards. This thesis uses eye movements and motor responses to divide driver perception-response time in three stages: perception, inspection, and movement time. The effects of cognitive distraction and repeated exposure on each stage were investigated for three distinct hazards (left-turning vehicle, pedestrian, right-incursion vehicle). In general, there were varying effects of cognitive distraction observed depending on the hazard being responded to. Cognitive distraction resulted in a significant increase in perception times for the pedestrian and right-incursion vehicle hazards, whereas cognitive distraction resulted in significantly longer inspection times for the left-turning vehicle hazard. When considering the effect of repeated scenario exposure, perception times were the most greatly affected. Perception times were significantly shorter during the second exposure to the left-turning vehicle hazard in the baseline condition, and for all hazards in the distraction condition.

A critical part of traffic safety is a driver’s ability to detect and respond to emergency roadway hazards. This thesis uses eye movements and motor responses to divide driver perception-response time in three stages: perception, inspection, and movement time. The effects of cognitive distraction and repeated exposure on each stage were investigated for three distinct hazards (left-turning vehicle, pedestrian, right-incursion vehicle). In general, there were varying effects of cognitive distraction observed depending on the hazard being responded to. Cognitive distraction resulted in a significant increase in perception times for the pedestrian and right-incursion vehicle hazards, whereas cognitive distraction resulted in significantly longer inspection times for the left-turning vehicle hazard. When considering the effect of repeated scenario exposure, perception times were the most greatly affected. Perception times were significantly shorter during the second exposure to the left-turning vehicle hazard in the baseline condition, and for all hazards in the distraction condition.

It is of interest that researchers study competing risks in which subjects may fail from any one of K causes. Comparing any two competing risks with covariate effects is very important in medical studies. This thesis develops omnibus tests for comparing cause-specific hazard rates and cumulative incidence functions at specified covariate levels. In the thesis, the omnibus tests are derived under the additive risk model, that is an alternative to the proportional hazard model, with by a weighted difference of estimates of cumulative cause-specific hazard rates. Simultaneous confidence bands for the difference of two conditional cumulative incidence functions are also constructed. A simulation procedure is used to sample from the null distribution of the test process in which the graphical and numerical techniques are used to detect the significant difference in the risks. A melanoma data set is used for the purpose of illustration.

This thesis centers on nonparametric inferences of the cumulative hazard function of a right truncated variable. We present three variance estimators for the Nelson-Aalen estimator of the cumulative hazard function and conduct a simulation study to investigate their performances. A close match between the sampling standard deviation and the estimated standard error is observed when an estimated survival probability is not close to 1. However, the problem of poor tail performance exists due to the limitation of the proposed variance estimators. We further analyze an AIDS blood transfusion sample for which the disease latent time is right truncated. We compute three variance estimators, yielding three sets of confidence intervals. This work provides insights of two-sample tests for right truncated data in the future research.

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