Testing for the Proportionality of Hazards in Two Samples Against the Increasing Cumulative Hazard Ratio Alternative

A number of tests of the proportional hazards hypothesis have been proposed in the past. In recent years, researchers have proposed tests geared specially for the alternative hypothesis of "increasing hazard ratio", keeping in mind the case of crossing hazards. This alternative may be too restrictive in many situations. In this paper we develop a test of the proportional hazards model for the weaker "increasing cumulative hazard ratio" alternative. The work is motivated by a data analytic example given by Gill & Schumacher (1987) where their test fails to reject the null hypothesis even though the faster ageing of one group is quite apparent from a plot. The normalized test statistic proposed here has an asymptotically normal distribution under either hypothesis. We also present two graphical methods related to our analytical test.     

Declining Share of Small Firms in U.S. Output: Causes and Consequences

We develop a dynamic general equilibrium model, with large and small firms, to examine possible causes and welfare implications of a declining trend in small firms' share of U.S. output since 1958. Numerical experiments indicate that recent technological advances and government tiering policies that have reduced fixed setup costs of production benefit the emergence of small firms, but lower their output share due to competition for resources among firms. However, this outcome is welfare improving. Therefore, if the policy objective is to raise small firms' output share and economic welfare simultaneously, it is desirable to concentrate on increasing antitrust and deregulatory efforts.     

Oil Spill Disruption and Problem Drinking: Assessing the Impact of Religious Context among Gulf Coast Residents

Population Research and Policy Review - While a wide body of research has indicated that social resources may be enhanced through religious practice, few studies have explored how social resources...     

Factors Driving Bribe Payments: Survey Evidence from Croatia

This research draws on a unique, large dataset of individuals in Croatia regarding their corruption experiences to analyze determinants of bribe payments. Taking account of economic, personal, social and geographic factors, results show that while greater competition for favors makes bribe offers more likely, females are less likely to offer bribes. A larger government size seems more focused on strengthening checks and balances rather than lengthening red tape. Robustness checks generally support these results.     

Supply chain performance and economic growth: The impact of COVID-19 disruptions

Reliable supply chains are crucial to the productivity and economic growth of nations. Despite the recognition of its importance, especially brought to the forefront by the challenges of the coronavirus crises, formal research on the contribution of supply chain logistics is less forthcoming. This paper uses data on 130 nations to examine the relative effects of different aspects of supply chain logistics, including overall logistics performance, and the performance of the input and output dimensions of logistics, on economic growth. The results show that improvements in the supply chain logistics performance yield positive growth dividends. Further, the input and output dimensions of logistics performance have positive growth effects, with some quantitative differences. Significantly, the growth impact of logistics performance varies across nations with different growth rates. Implications for public policy and spillovers for COVID-19 initiatives are discussed.     

Fishing Households,Social Support,and Depression after the Deepwater Horizon Oil Spill

This study contributes to the growing body of knowledge on mental health in the aftermath of disasters by examining depressive symptoms among residents of the U.S. Gulf Coast region 6 years after the onset of the Deepwater Horizon oil spill (DHOS). Using data from the Survey of Trauma, Resilience, and Opportunity in Neighborhoods in the Gulf (STRONG), we test how social support and ties to the fishing industry are related to the likelihood of a positive depression screen. The results show that, among most residents of the Gulf Coast region, social support holds an inverse relationship with the likelihood of a positive depression screen. However, among fishing households, greater social support is associated with a higher probability of screening positive for depression. By showing that fishing households with greater social support are more susceptible to depressive symptoms in this setting, our results uncover a potentially important mechanism that contributes to the unique vulnerability of fishers, which in turn holds implications for differential impacts across social groups in environmental disaster contexts.     

Disaster preparedness among households in the Badakhshan Province in Afghanistan: A baseline evaluation study

This paper presents a critical analysis of the level of disaster preparedness among households in the Badakhshan Province in Afghanistan. Based on an analysis of baseline data collected as part of a project aimed at strengthening the disaster response in this province, this paper emphasizes the complexities of disaster preparedness among Afghan households, including a critical gap in knowledge, a lack of resources, and limitations in existing community responses to disasters. The findings reveal that less economic security, less knowledge of emergencies and emergency plans, being a female head of household, and having prior disaster experience tended to predict lower levels of preparedness among households. Disaster‐preparedness interventions targeted at improving the knowledge of hazards and hazard plans, as well as enhancing the livelihood and income security of affected households, could minimize the negative impact of disasters. Because most households relied on social networks and indigenous preparedness measures, future research should examine the nature of such measures and their effectiveness in mitigating the impact of disasters on this population.