A Brief Survey of Modern Optimization for Statisticians

Modern computational statistics is turning more and more to high‐dimensional optimization to handle the deluge of big data. Once a model is formulated, its parameters can be estimated by optimization. Because model parsimony is important, models routinely include non‐differentiable penalty terms such as the lasso. This sober reality complicates minimization and maximization. Our broad survey stresses a few important principles in algorithm design. Rather than view these principles in isolation, it is more productive to mix and match them. A few well‐chosen examples illustrate this point. Algorithm derivation is also emphasized, and theory is downplayed, particularly the abstractions of the convex calculus. Thus, our survey should be useful and accessible to a broad audience.     

Prosecutorial Discretion at the EPA: Some Evidence on Litigation Strategy

This paper examines the determinants of the EPAs litigation strategy between 1977 and 1996 focusing on the tenure of Ann Gorsuch. Two hypotheses about this period are tested: (1) that changes in the EPAs litigation strategy were in fact an effort to reduce the expected penalty for violating environmental laws or (2) that the changes made in litigation strategy were consistent with efforts to reduce transaction cost. Contrary to previous research, I find no conclusive evidence of an overall shift toward business interests in EPA prosecutions. There is, however, clear evidence of shifts in the EPAs litigation strategy across administrations.     

Predicting bankruptcy in the Texas nursing facility industry

Approximately 50% of nursing facilities in Texas petitioned for bankruptcy during the 1998–2004 period. Using a logit regression model tested for robustness, we find nursing facilities that are profit-seekers, chain members, pay higher than average wage rates, accept more intensive-care residents and obtain a larger than average portion of their funding from public sources are highly vulnerable to negative changes in regulatory policy decisions on Medicare and Medicaid reimbursement. Larger facilities having higher than average occupancy rates and quality of care are less susceptible to adverse decisions. The model correctly classifies a facility as either bankrupt or solvent in about 75% of cases. We also examine the duration of bankruptcy using accelerated failure-time models. It appears that the duration of bankruptcy depends on location, out-of-state ownership, length of ownership, volume of resident days supplied, total cost and proportion of revenues from Medicaid.     

Increasing consumer well-being: risk as potential driver of happiness

This article investigates the relation between risk and individual well-being. We propose a theoretical model of happiness that makes a distinction between ex ante evaluations of happiness and ex post assessments. The main assumptions of the model are tested through three studies based on anchoring vignettes. We show that, even if, ex ante, consumers fear high risk and do not associate it to a high level of happiness, their ex post evaluation of well-being is generally higher when identical consequences result from a high-risk situation than from a low-risk situation. Control over risk-taking reinforces the gap between ex ante and ex post measures of happiness. Thus, our article provides empirical evidence about a positive relation between risk and individual well-being, suggesting that risky experiences have the potential to increase consumer well-being.     

Resource Accounting in Measures of Unsustainability: Challenging the World Bank's Conclusions

The World Bank has recently published acomprehensive study of environmental and resourceaccounting, covering 103 countries (World Bank1997a). The study concludes that many Sub-Saharan,Northern African and Middle East countries have hadnegative `genuine' saving rates over the last 20years and therefore fail to pass the test of weaksustainability. This paper argues that the Bank'sconclusions depend on a method for computing usercosts from resource exploitation that is challengedby two competing ones (the `El Serafy'-method andthe method of Repetto et al.) and is inferior to oneof its rivals. Resource rents are re-computed usingthe `El Serafy'-method for 14 countries and theSub-Saharan and Northern African and Middle Eastregions. The results are that both regions andalmost all countries either stop exhibiting signs ofunsustainability or their unsustainability can beexplained without having recourse to resourceaccounting. However, for Congo, Ecuador, Gabon,Nigeria, Mauritania and Trinidad and Tobago there isa lesson: These countries did not adequately use theopportunities they were given through their naturalresource endowments and should learn from theirmistake for the future depletion of their remainingreserves of natural resources.     

Comparing the impacts of Internet technology and national culture on online usage and purchase from a four-country perspective

The Internet has successfully generated an ever-expanding cohort of users for all its major concomitant activities, including information gathering, communications and transactions. So far no attempt has been made to validate whether such a success is so deep as to transcend national cultures. Nor any work has been conducted to compare the internationalisation¹ performances between online usage activities. The current study addresses these two research gaps from the perspective of four countries, i.e. Britain, Germany, Japan and Taiwan. Results show that although the technological forces have been quite successful in internationalising overall online usage activities, they succumb to the cultural forces as far as only the transactions activity, or more colloquially online purchase, is concerned. This indicates the relative difficulty in internationalising online purchase vis-à-vis other online usage activities. Further research on locating a series of step functions or kick-off time points regarding the development of online purchase is suggested.     

Design and implementation of the Expanded Public Works Programme: Lessons from the Gundo Lashu labour-intensive programme

This article examines the design and implementation of the Expanded Public Works Programme, drawing from the lessons of the Gundo Lashu programme on labour-intensive construction in the road sector. The aim of the study was to examine major barriers to the design and implementation of the programme. The article is based on the analysis of data that were gathered from the Gundo Lashu programme. The data were collected using a structured questionnaire, face-to-face interviews with the project participants as well as reviewing key secondary data from the project documents. The study found that the projects under the Gundo Lashu programme have clearly demonstrated the importance of labour-intensive approaches, especially in the road sector. However, these projects were constrained by a wide range of challenges, ranging from a lack of community participation to poor product quality and inadequate planning for sustainable financing.