Reduction in Dietary Acrylamide Exposure—Impact of Potatoes with Low Acrylamide Potential

Acrylamide forms primarily from a reaction between reducing sugars (e.g., glucose and fructose) and an amino acid (asparagine, Asn) formed naturally in foods, including potatoes. This reaction occurs when carbohydrate‐rich foods are heated at temperatures above 120 °C. Multiple potato varieties were transformed with potato genomic DNA that results in down‐regulation of the expression of the asparagine synthetase‐1 gene (Asn1), significantly reducing synthesis of free Asn, and consequently lowering the potential to form acrylamide during cooking. These potatoes with low acrylamide potential (LAP) were tested in agronomic trials, and processed into French fries and potato chips. Decreased levels of acrylamide were measured in these cooked food products when derived from LAP potatoes compared with those derived from conventional potatoes. These reductions can be directly attributed to reduction in Asn levels in the LAP potatoes. The corresponding average reduction in exposure to acrylamide from French fry and potato chip consumption is estimated to be 65%, which would amount to approximately a 25% reduction in overall dietary exposure. Considering that children consume nearly three times more acrylamide than adults on a per kg body weight basis, they would experience the most impact from the reduced acrylamide associated with LAP potatoes. The potential public health impacts, in context of dietary acrylamide exposure reduction, are discussed in this study.     

The Use of Simulation to Reduce the Domain of “Black Swans” with Application to Hurricane Impacts to Power Systems

Recently, the concept of black swans has gained increased attention in the fields of risk assessment and risk management. Different types of black swans have been suggested, distinguishing between unknown unknowns (nothing in the past can convincingly point to its occurrence), unknown knowns (known to some, but not to relevant analysts), or known knowns where the probability of occurrence is judged as negligible. Traditional risk assessments have been questioned, as their standard probabilistic methods may not be capable of predicting or even identifying these rare and extreme events, thus creating a source of possible black swans. In this article, we show how a simulation model can be used to identify previously unknown potentially extreme events that if not identified and treated could occur as black swans. We show that by manipulating a verified and validated model used to predict the impacts of hazards on a system of interest, we can identify hazard conditions not previously experienced that could lead to impacts much larger than any previous level of impact. This makes these potential black swan events known and allows risk managers to more fully consider them. We demonstrate this method using a model developed to evaluate the effect of hurricanes on energy systems in the United States; we identify hurricanes with potentially extreme impacts, storms well beyond what the historic record suggests is possible in terms of impacts.     

Building a Values‐Informed Mental Model for New Orleans Climate Risk Management

Individuals use values to frame their beliefs and simplify their understanding when confronted with complex and uncertain situations. The high complexity and deep uncertainty involved in climate risk management (CRM) lead to individuals’ values likely being coupled to and contributing to their understanding of specific climate risk factors and management strategies. Most mental model approaches, however, which are commonly used to inform our understanding of people's beliefs, ignore values. In response, we developed a “Values‐informed Mental Model” research approach, or ViMM, to elicit individuals’ values alongside their beliefs and determine which values people use to understand and assess specific climate risk factors and CRM strategies. Our results show that participants consistently used one of three values to frame their understanding of risk factors and CRM strategies in New Orleans: (1) fostering a healthy economy, wealth, and job creation, (2) protecting and promoting healthy ecosystems and biodiversity, and (3) preserving New Orleans’ unique culture, traditions, and historically significant neighborhoods. While the first value frame is common in analyses of CRM strategies, the latter two are often ignored, despite their mirroring commonly accepted pillars of sustainability. Other values like distributive justice and fairness were prioritized differently depending on the risk factor or strategy being discussed. These results suggest that the ViMM method could be a critical first step in CRM decision‐support processes and may encourage adoption of CRM strategies more in line with stakeholders’ values.     

Dual class shares,board of directors’ effectiveness and firm’s market value: an empirical study

This study aims to identify whether a relationship exists between the controlling shareholders’ voting power and outside directors’ effectiveness in maximizing firms’ financial performance. We analyze a panel data with 3057 observations for the 2000–2012 period using a random effects model, logit and probit regressions, and the two-stage model of Heckman in the Brazilian stock market. Our findings show that firms whose controlling shareholders use dual class shares to leverage their voting power have less independence from the board and worse financial performance and market value. Further, the percentage of outside directors tends to be ineffective in increasing the firm’s value, and in changing the firm’s chief executive officer (CEO) when (1) the controlling shareholder’s voting power is leveraged, or (2) when the CEO assumes a position on the board of directors simultaneously. We interpreted that these results are in line with the arguments in favor of the existence of a new agency cost, which is related to the undue obedience of board members to authority, such as the largest controlling shareholder or the CEO in Brazilian listed firms.     

中国省区城市化水平的马尔可夫预测

首先将中国省区的城市化水平划分为四种状态,并建立一个吸收的Markov随机过程,描述中国省区城市化水平状态的变化规律;其次,利用Markov预测模型,对省区城市化水平的变动趋势进行预测;最后,通过吸收Markov链的基本矩阵,对各种"非吸收状态"进入"吸收状态"(高度城市化水平状态)所需的时间进行预测,并对其进行分析.     

Acquisition of Telecommunications Bandwidth Under Economies of Scale in Size and Duration of Contracts*

Significant advances in information technology have brought about increased demand for bandwidth. Buyers of bandwidth often encounter bandwidth prices that are decreasing over time. Additionally, bandwidth prices at any point in time are decreasing in total bandwidth purchased and length of contracts. Therefore, buyers face complex decisions in terms of the number of contracts to buy, their bandwidth, and their lengths. In this article, we formulate models for the acquisition of bandwidth from a buyer's perspective. We begin with a model that allows varying contract durations under deterministic demand and without allowing shortages or overlapping contracts. We then formulate a simpler model, which restricts contract lengths over the planning horizon to be equal. We also solve the problem under probabilistic demand and allowing for shortages, which are satisfied by buying additional bandwidth at a premium. We perform numerical sensitivity analysis to compare the results of the models and illustrate the results with numerical examples. The numerical analyses illustrate that using relatively simple equal‐length contracts produces approximately the same results as the more complicated unequal‐length contract strategy.     

TOP INCOMES IN THE NETHERLANDS AND THE UNITED KINGDOM OVER THE 20TH CENTURY

A method is developed for using income‐tax data to investigate the evolution of the highest incomes over virtually the entire 20th century. The income shares of the top 10, 5, 1, 0.5, 0.1, and 0.05 percent are analysed for the UK and the Netherlands. For considering the top shares among themselves the “Pareto–Lorenz coefficient” is proposed. Between the two countries, the top shares appear to undergo a strikingly similar and strong decline up to the mid‐1970s. Since then British top shares have increased significantly while Dutch shares remained basically unchanged. This outcome parallels similar results for the US and France obtained by Piketty and Saez and poses interesting questions for research. (JEL: N34, D31, O15)     

THE REPLACEMENT PROBLEM IN FRICTIONAL ECONOMIES: A NEAR‐EQUIVALENCE RESULT

We examine how technological change affects wage inequality and unemployment in a calibrated model of matching frictions in the labor market. We distinguish between two polar cases studied in the literature: a “creative destruction” economy, where new machines enter chiefly through new matches and an “upgrading” economy, where machines in existing matches are replaced by new machines. Our main results are: (i) these two economies produce very similar quantitative outcomes, and (ii) the total amount of wage inequality generated by frictions is very small. We explain these findings in light of the fact that, in the model calibrated to the US economy, both unemployment and vacancy durations are very short, i.e., the matching frictions are quantitatively minor. Hence, the equilibrium allocations of the model are remarkably close to those of a frictionless version of our economy where firms are indifferent between upgrading and creative destruction, and where every worker is paid the same market‐clearing wage. These results are robust to the inclusion of machine‐specific or match‐specific heterogeneity into the benchmark model. (JEL: J41, J64, O33)     

A New Look at the Psychometric Paradigm of Perception of Hazards

The psychometric paradigm has been the most influential model in the field of risk analysis. The "cognitive maps" of hazards produced by the paradigm seem to explain how laypeople perceive the various risks they face. Because most of the studies used aggregated data, analyzed using principal component analysis, it is not known whether the model neglects individual differences in risk perception. There has been much criticism on the fact that few studies have examined individual differences in the cognitive representation of hazards. In order to detect and describe the internal structure of the three-way data, we conducted a three-way component analysis (3MPCA). Data for the present analysis were derived from a mail survey conducted in Switzerland. Participants were asked to judge 9 attributes for 26 hazards. Individual differences in the cognitive representation of hazards were correlated with external variables (e.g., general trust). The results suggest that methods permitting individual differences should be used more frequently and that utilizing different methods could provide greater insight into the cognitive representation of risks.