Estimating the impact of incidents on urban controlled-access highways: an empirical analysis

An empirical analysis is developed that quantifies the impact of different types of traffic incidents on the speed and maximum flow averages of vehicles on a controlled-access highway. The incident types considered include damage to highway infrastructure, vehicle rollover, crashes (into stationary objects), collisions (with moving vehicles), rain, fog, vehicle breakdowns, pedestrians on roadway, etc. Using real-world data from Chile’s most heavily used urban motorway/freeway, estimates of incident impacts on speed are generated using a multiple linear regression model incorporating instrumental variables to correct for endogeneity. Flow results are then generated using the fundamental traffic equation relating speed, flow and density. A ranking of the impacts on highway traffic of the different incident types based on incident frequency as well as impact size demonstrates that for the real case studied, the incidents with the greatest cumulative effect are (in order of magnitude) vehicle breakdown, collisions and rain.     

Estimates of price elasticity of demand for urban freeway use with high-frequency control variables: the case of Santiago,Chile

Estimates are presented of toll and fuel price elasticities of demand for urban freeway use in Santiago, Chile. High-frequency toll and vehicle data were collected from four urban freeways for different route segments and times of day. Estimation was performed using log-linear regression models whose explanatory variables were tolls, fuel prices, city traffic levels and sets of dichotomous variables to control for daily, weekly and monthly seasonality. City traffic is a high frequency control of the activity level of the city. The elasticities to changes in tolls and fuel were all low in absolute value. The toll elasticities were below 0.05 for two freeways and 0.16 for the third, while for the fourth, which had more alternative routes, it was 0.47. The fuel price elasticities were also heterogeneous, with values of approximately 0.45 for two freeways and 0.21 for the third whereas for the fourth, which had the fewest alternatives, it was 0.07.     

Capability-based governance patterns over the product life-cycle: an agent-based model

In recent literature, there is disagreement over the temporal pattern of vertical governance of firms over the product life-cycle. We use a novel neo-Schumpeterian agent-based simulation model to investigate emerging patterns of vertical governance for different levels of imitability and substitutability of capabilities. We find that, in the mature phase of the product life-cycle, firms generally prefer vertical specialization. However, in the early phase, imitability and substitutability, in interplay, determine the governance form preferred. High imitability frustrates appropriation and thereby discourages integration for synergistic advantages. However, firms need not vertically specialize: under low substitutability, incompatibilities reduce the advantages of specialization. When both substitutability and imitability are low, firms can appropriate the value of their inventions and there is no combinatorial advantage of specialization, so firms predominantly integrate. If substitutability is high and imitability is low, the combinatorial advantage of specialization balances with the synergistic advantage of integration.     

非均衡发展战略中的区域整合——珠江三角洲与省内相邻区个案研究

非均衡的区域发展是区域发展的一种常态结构。如何在此种结构下,实现发达地区与不发达地区的整合发展,是一项挑战性的课题。通过珠江三角洲与省内邻区区域整合的案例分析,本文认为,在非均衡发展战略下,要实现区域整合发展,除了有效的政府干预外,建立有效的区域整合机制是实现区域整合发展的关键。     

Long-term investment sensitivity to cash flow and financial crisis

This study examined investment–cash flow sensitivity in unconstrained and constrained firms from 1980 to 2010 in a sample of Italian manufacturing firms. Investment sensitivity to cash flow decreased over time, and financially constrained firms showed little difference in the decline compared with unconstrained firms. Last, investment sensitivity to cash flow increased during the financial crisis of 2008.     

Georges Perrin and the GP cost calculation method: the story of a failure

After the Second World War, a number of costing methods were developed in France in response to the perceived limitations of Rimailho's 'homogeneous sections' method. The common feature of all these methods was the provision of a more thorough analysis of operations through the adoption of techniques which were simple to use. The GP method, developed by Georges Perrin, was the most successful but, despite its many advantages, its success was limited, due to deficiencies in Perrin's communication policy and his network of contacts.     

Surveillance of interpersonal violence in Kingston,Jamaica: an evaluation

Injuries are among the leading causes of death in Jamaica. Homicide rates have been sharply increasing since 1991. In 1997, the rate of homicide (45/100 000) in Jamaica was over five times the US rate in 1997 (7.9/100 000). In response to this problem and the alarming increase in non-fatal assaultive injuries, the Jamaican Ministry of Health together with the CDC established a Violence-Related Injury Surveillance System (VRISS) using patient registration data from Kingston Public Hospital. The VRISS was evaluated for usefulness, and for system attributes: system acceptability, simplicity, flexibility, sensitivity, and predictive value positive (PVP). System-identified cases were compared with clinical records and data from direct patient interviews. The surveillance system was flexible, acceptable to clinical staff and Ministry officials, and moderately sensitive, detecting 62% to 69% of violent injuries identified from clinical records and a patient survey. The system's predictive value positive was high, with 86% of potential cases confirmed as actual cases. Although adequate, system sensitivity was reduced by incomplete or no registration of patients during periods of staff shortage. In conclusion, despite some logistic shortcomings, the system appeared promising for collecting limited information on non-fatal interpersonal violent injuries. With modification and expansion, the system may be capable of collecting unintentional-injury data also.     

Government Ownership of Banks

We assemble data on government ownership of banks around the world. The data show that such ownership is large and pervasive, and higher in countries with low levels of per capita income, backward financial systems, interventionist and inefficient governments, and poor protection of property rights. Higher government ownership of banks in 1970 is associated with slower subsequent financial development and lower growth of per capita income and productivity. This evidence supports "political" theories of the effects of government ownership of firms.