Competitive bidding — The probability of winning

A company bidding by sealed tender needs to know the relationship between their bid price and their chances of winning the contract. Previously published models for computing the probability of winning are examined and found to be inaccurate. The problem is reformulated, and a new general predictive model for computing the probability of winning is developed. The method of computation is illustrated by a simple worked example.     

A Longitudinal Analysis of Adolescent Substance Use and School Motivation Among African American Youth

Cross‐sectional research has shown a link between adolescent substance use and educational motivation. The purpose of the current study was to examine this link in a longitudinal sample of African American youth. The study examined the interrelationships between alcohol and both marijuana use and school motivation over the high school years and their effect on graduation in 681 African American adolescents (50.8% female). School motivation was shown to relate to subsequent alcohol use throughout high school and marijuana use early in high school. School motivation did not affect graduation status, but alcohol and marijuana use were related to a lower likelihood of graduating from high school. Some gender differences and differences among those who had tried alcohol or marijuana at the first wave as opposed to those who had not tried each substance were found. The findings support a systems model where school experiences can affect substance use, which, in turn, can affect the completion of high school.     

黄河首曲生态环境现状与社会经济发展对策研究

黄河首曲生态环境的好坏不仅影响当地的社会经济发展,而且影响黄河流域社会经济的可持续发展。因此,全社会要高度重视首曲草地生态的功能和作用,从人与自然和谐共处、社会经济可持续发展的高度认识定位生态环境。本文通过实地调查,对黄河首曲生态环境恶化的原因进行了分析,并就如何治理生态环境,以及社会经济可持续发展提出了对策与建议。     

Productivity of highly skilled immigrants: economists in the postwar period

Prior work finds declining immigrant quality in the postwar period that is linked to source-country and skill-composition changes associated with the 1965 Immigration Act. This paper uses a unique panel of foreign- and native-born American Economic Association members to show that the highly skilled experienced a similar shift away from European migrants toward those from Asia. However, the findings do not indicate that this change in source-country composition has been accompanied by a decline in quality; rather, the most recent cohorts of foreign-born economists appear to be more productive than their native counterparts.     

Rolling with the shakes: an insight into teenagers’ perceptions of recovery after the Canterbury earthquakes

Natural disasters are harmful worldwide events that inflict multiple psychosocial impacts on disaster-exposed individuals. A significant proportion of affected individuals are teenagers (13–18 years old) who, compared with adults, have been historically overlooked in disaster research. The literature is particularly sparse concerning teenagers’ recovery from natural disasters, specifically what recovery means to them and the contributing factors towards their positive recovery. Therefore, the aim of the current study was to gain deeper insight into this largely unexplored area by conducting five focus groups with teenagers (16–18 years) who experienced at least one of the Canterbury, New Zealand, earthquakes since and including the initial September 2010 earthquake. This study directly asked teenagers about their recovery over the three years after the initial earthquakes, with data being analysed using thematic analysis. Two main themes were identified: (1) perceptions of recovery, with three sub-themes (i) knowledge and being less frightened, (ii) talking about the earthquakes and (iii) shift in perspectives; and (2) contributing factors to recovery, with three sub-themes (i) participation in the community response, (ii) returning to school and (iii) the rebuild of Christchurch. These factors provide insight into how we can better support the recovery process for disaster-exposed teenagers to reduce long-term distress.     

A common-features analysis of Amsterdam and London financial markets during the eighteenth century

We examine the financial linkage between the London and Amsterdam financial markets using stock prices recorded in each market over the period 1723-94 in conjunction with tests for common trends, cycles, and regime shifts. These tests reveal a surprising degree of integration between the markets as their prices move together in both the short and long run. Moreover, shocks to the assets translate quickly and accurately between markets. It also appears that Dutch investment did not destabilize London markets and stock prices in London were the primary determinant of prices in Amsterdam.     

Improving homeless persons' utilisation of primary care: lessons to be learned from an outreach programme in The Netherlands

Elissen AMJ, Van Raak AJA, Derckx EWCC, Vrijhoef HJM. Improving homeless persons' utilisation of primary care: lessons to be learned from an outreach programme in The Netherlands Faced with rising homelessness, countries around the world are in need of innovative approaches to caring for those without shelter, who, more often than not, suffer from severe health problems. We conducted a case study of an innovative Dutch Primary Care for the Homeless (PCH) programme to gain insight into clients' demographic characteristics, health problems and service use, and to develop an explanation for its success in increasing the latter. Our analyses are based on a combination of quantitative and qualitative data. The results of the study suggest that the success of the PCH programme can be explained by the providers' pragmatism and will to adapt their mode of care provision to the behavioural patterns and needs of their homeless clients.     

The Face-to-Face Light Detection Paradigm: A New Methodology for Investigating Visuospatial Attention Across Different Face Regions in Live Face-to-Face Communication Settings

We introduce a novel paradigm for studying the cognitive processes used by listeners within interactive settings. This paradigm places the talker and the listener in the same physical space, creating opportunities for investigations of attention and comprehension processes taking place during interactive discourse situations. An experiment was conducted to compare results from previous research using videotaped stimuli to those obtained within the live face-to-face task paradigm. A headworn apparatus is used to briefly display LEDs on the talker's face in four locations as the talker communicates with the participant. In addition to the primary task of comprehending speeches, participants make a secondary task light detection response. In the present experiment, the talker gave non-emotionally-expressive speeches that were used in past research with videotaped stimuli. Signal detection analysis was employed to determine which areas of the face received the greatest focus of attention. Results replicate previous findings using videotaped methods.