Risk Analysis, Vol. 34, No. 12, 2014
DOI: 10.1111/risa.12338
From the Editors
EXPOSURE ESTIMATION FROM POPULATION AND DIARY SAMPLING
can be used to improve safety of underground storage systems. They show how to use simple risk models, such as small fault trees, consequence trees, risk matrices, and “Swiss cheese” models of organizational and procedural controls and vulnerabilities, to organize thinking and re-use understanding of hazards gained in one context (above-ground storage) to help reduce risks in another (underground storage). They find that analysis of above-ground accidents using these tools can indeed help to suggest early warning indicators and improve safety procedures that reduce risks of fires, blocked flows of coal due to freezing on cold weather, and occupational accidents in underground coal storage.
Che et al. consider the effects of different population-sampling and diary-sampling methods on estimates of children’s exposure to fine particulate matter (PM2.5). They find only minor differences in estimated mean average daily exposures using two different population sampling methods (with and without stratification), but estimates are more sensitive to methods for simulating diary sampling over time, especially for estimates of the number of individuals with exposures in excess of a benchmark level. Which method is most accurate is not yet clear. TATTOOS AND CRIMINAL BEHAVIOR
USING HYBRID BAYESIAN NETWORKS (BNS) TO MODEL ACCIDENT RISKS WITH SCARCE INFORMATION
Lioa et al. present empirical evidence from a sample of juvenile detainees in Taiwan that those with tattoos are more likely than otherwise similar matched detainees without tattoos to commit fraud, assault, drug abuse, and homicide (by 3%, 13%, 9%, and 9%, respectively), but not robbery or burglary. One possible explanation is that tattooing is associated with membership in gangs in Taiwan. Another might be that underlying factors, such as sensation-seeking personality traits, explain some of the covariance in both tattoos and criminal behavior. The article illustrates the use of “coarsened exact matching”—in which continuous variables such as age are initially coarsened into ordered categories for purposes of matching cases and controls, or tattooed and nontattooed subjects—as a useful alternative to more complex and less robust statistical methods such as propensity score matching. This technique may be of value to other epidemiologists and risk analysts interested in identifying the effects of risk factors or markers on probabilities of undesirable outcomes.
BNs can extend and complement traditional probabilistic risk assessment (PRA) techniques such as fault tree analysis by making it easier to represent non-binary variables and dependencies among failures and by automatically propagating evidence to draw inferences about probabilities based on observations. Martins et al. describe and illustrate in detail how to convert fault trees to hybrid (mixed discrete and continuous variables) BNs and carry out a complete PRA for the regasification system of a liquefied natural gas (LNG) floating storage and regasification unit, for which there is limited operational experience. The BN provides a way to integrate limited available data and knowledge into a PRA. Recent computational methods and approximations, discussed in the article, make it practical to use hybrid BNs with quite general continuous probability distributions. The analysis culminates in F-N (Farmer) curves for frequencies of different numbers of fatalities per year, together with tornado diagrams showing the sensitivity of expected time until a medium LNG leak to different component failure rates. These outputs help to identify recommendations for reducing risks (e.g., by improving the reliability of critical valves), even in the absence of extensive operating experience.
TRANSFERRING RISK MANAGEMENT KNOWLEDGE ACROSS CONTEXTS TO IMPROVE COAL MINING SAFETY Sipila¨ et al. investigate whether knowledge and experience gained in above-ground storage of coal 2063
C 2014 Society for Risk Analysis 0272-4332/14/0100-2063$22.00/1
2064 USING RISK PSYCHOLOGY TO BETTER DETECT AND DEFEND AGAINST E-MAIL ATTACKS E-mail scammers use a variety of psychological techniques in “phishing” attacks to gain trust, manipulate emotions (such as fear, greed, or pity), create a sense of urgency, and exploit System 1 responses to induce recipients to disclose sensitive information. These attacks have succeeded at major organizations, from the White House to Coca Cola to the Reserve Bank of Australia. Incorporation of credible personal information, such as making the e-mail seem to come from someone that the recipient knows, dramatically increases the probability that the recipient will perceive it as legitimate and take the action that the scammer wants. Kaivanto modifies classical signal detection theory to incorporate psychologically realistic descriptions of perceptions and responses, modeled using Prospect Theory (PT), rather than assuming perfectly rational (expected utility maximizing, System 2) behaviors. Agent-based modeling simulating the responses of networks or organizations of realistically-behaving agents to sustained phishing attacks shows that incorporating PT models of individual responses can significantly affect risk estimates and yield new insights into how best to protect organization from such attacks.
EXPRESSING RISK INFORMATION WITH RISK NUMBERS OR CATEGORIES MacKenzie critically examines the widespread practice of summarizing, comparing, tracking, and communicating risk information using ordered categories or numerical scores (generically called “risk indices”). He identifies flaws in popular risk index methods such as risk matrices, and recommends a constructive procedure for developing sounder and more useful risk indices. This approach distinguishes clearly between risk indices and more demanding quantitative measures of risk, e.g., based on moments, quantiles, utility-based shortfall risk measures, or multifactor models. The procedure is illustrated by constructing risk indices to support comparison of fatality risks across three transportation models: commercial air carriers, on-demand or chartered air taxis/commuters, and highway. Which mode is considered riskiest depends on the underlying risk measure, but air taxis are riskiest by most measures and indices considered. The article not only shows how to move from mathematical
From the Editors measures of risk based on probability distributions to simpler risk indices, e.g., on a scale from 0 to 100, but also emphasizes how clear explanation of the exact meaning and intended interpretation of the resulting numbers—which should accompany every proposed risk index—can help to promote clear thinking and more effective communication between risk analysis practitioners and those who use their results. DOES THE PRECAUTIONARY PRINCIPLE STIFLE SCIENCE AND INNOVATION? Although many have argued that precautionary regulation tends to reduce the role of sound science in regulation, Todt and Luj´an argue that, in principle, precautionary regulation is not necessarily opposed to scientific-technological development, and could even stimulate improvements in scientific method and knowledge, even though, in practice, some applications of precaution may impede scientific analysis and specific innovations. After reviewing controversies over precaution, such as that it may divert resources to speculative hazards or impose opportunity costs that are not properly weighed against benefits, the authors consider ways in which precaution might be based on academic or decision-oriented science. They conclude that precautionary regulation can encourage innovation and may be able to help reconcile the goals of promoting and controlling science and technology. EFFICIENT INSPECTION FOR CERTIFYING ORGANIC PRODUCTS To certify that products marketed as being organic comply with relevant definitions and standards for what constitutes “organic” produce, the European Union relies on costly inspections of conditions on farms. Zanoli et al. consider the statistical challenges that arise in analysis of inspection data over time (farm-level panel data) and discuss the potential for risk-based approaches to noncompliance to improve the efficiency and cost-effectiveness of the certification process. They recommend statistical procedures (e.g., zero-inflated Poisson regression models of count data for slight and severe sanctions) for estimating the probability of non-compliance from predictors such as past compliance history, farm size, and presence of animals on the farm. Weighting this probability by the consequences of noncompliance (as indicated by corresponding sanctions, used as a proxy for severity) yields a risk-based
From the Editors approach to inspection. The authors caution that successful implementation of risk-based inspection strategies is difficult, in part because data on farm and farmer characteristics are limited, and in part because the relations between risk factors and the risks that they predict may change in the future. This issue concludes with a review by Roger Kasperson of the recent book The Risk Society Revisited: Social Theory and Governance, by Eugene Rosa, Ortwin Renn, and Aaron McCright. Kasperson notes that the book helps to fill a persistent void in North American thinking about society and risk, the role of the social sciences in risk analysis and management, and the place of risk in social theory, by drawing on a rich European intellectual tradition of social theory. Kasperson
2065 praises the book highly: “For risk scholars, this is the most coherent and lucid analysis of the contributions and limitations of these important social theorists to risk thinking that can be found in the literature. . . . [It] is the most sophisticated and deep exploration of social theory and its potential role in risk analysis and management available.” Particularly noteworthy is the book’s contribution to thinking about risk governance (as opposed to mere government) and fruitful analytic-deliberative processes in a world of realistic complexity, and uncertainty, where wise risk governance must address overlapping concerns about social justice, inequities, psychological stresses, and conflicts. Tony Cox and Karen Lowrie
DOI: 10.1111/risa.12338
From the Editors
EXPOSURE ESTIMATION FROM POPULATION AND DIARY SAMPLING
can be used to improve safety of underground storage systems. They show how to use simple risk models, such as small fault trees, consequence trees, risk matrices, and “Swiss cheese” models of organizational and procedural controls and vulnerabilities, to organize thinking and re-use understanding of hazards gained in one context (above-ground storage) to help reduce risks in another (underground storage). They find that analysis of above-ground accidents using these tools can indeed help to suggest early warning indicators and improve safety procedures that reduce risks of fires, blocked flows of coal due to freezing on cold weather, and occupational accidents in underground coal storage.
Che et al. consider the effects of different population-sampling and diary-sampling methods on estimates of children’s exposure to fine particulate matter (PM2.5). They find only minor differences in estimated mean average daily exposures using two different population sampling methods (with and without stratification), but estimates are more sensitive to methods for simulating diary sampling over time, especially for estimates of the number of individuals with exposures in excess of a benchmark level. Which method is most accurate is not yet clear. TATTOOS AND CRIMINAL BEHAVIOR
USING HYBRID BAYESIAN NETWORKS (BNS) TO MODEL ACCIDENT RISKS WITH SCARCE INFORMATION
Lioa et al. present empirical evidence from a sample of juvenile detainees in Taiwan that those with tattoos are more likely than otherwise similar matched detainees without tattoos to commit fraud, assault, drug abuse, and homicide (by 3%, 13%, 9%, and 9%, respectively), but not robbery or burglary. One possible explanation is that tattooing is associated with membership in gangs in Taiwan. Another might be that underlying factors, such as sensation-seeking personality traits, explain some of the covariance in both tattoos and criminal behavior. The article illustrates the use of “coarsened exact matching”—in which continuous variables such as age are initially coarsened into ordered categories for purposes of matching cases and controls, or tattooed and nontattooed subjects—as a useful alternative to more complex and less robust statistical methods such as propensity score matching. This technique may be of value to other epidemiologists and risk analysts interested in identifying the effects of risk factors or markers on probabilities of undesirable outcomes.
BNs can extend and complement traditional probabilistic risk assessment (PRA) techniques such as fault tree analysis by making it easier to represent non-binary variables and dependencies among failures and by automatically propagating evidence to draw inferences about probabilities based on observations. Martins et al. describe and illustrate in detail how to convert fault trees to hybrid (mixed discrete and continuous variables) BNs and carry out a complete PRA for the regasification system of a liquefied natural gas (LNG) floating storage and regasification unit, for which there is limited operational experience. The BN provides a way to integrate limited available data and knowledge into a PRA. Recent computational methods and approximations, discussed in the article, make it practical to use hybrid BNs with quite general continuous probability distributions. The analysis culminates in F-N (Farmer) curves for frequencies of different numbers of fatalities per year, together with tornado diagrams showing the sensitivity of expected time until a medium LNG leak to different component failure rates. These outputs help to identify recommendations for reducing risks (e.g., by improving the reliability of critical valves), even in the absence of extensive operating experience.
TRANSFERRING RISK MANAGEMENT KNOWLEDGE ACROSS CONTEXTS TO IMPROVE COAL MINING SAFETY Sipila¨ et al. investigate whether knowledge and experience gained in above-ground storage of coal 2063
C 2014 Society for Risk Analysis 0272-4332/14/0100-2063$22.00/1
2064 USING RISK PSYCHOLOGY TO BETTER DETECT AND DEFEND AGAINST E-MAIL ATTACKS E-mail scammers use a variety of psychological techniques in “phishing” attacks to gain trust, manipulate emotions (such as fear, greed, or pity), create a sense of urgency, and exploit System 1 responses to induce recipients to disclose sensitive information. These attacks have succeeded at major organizations, from the White House to Coca Cola to the Reserve Bank of Australia. Incorporation of credible personal information, such as making the e-mail seem to come from someone that the recipient knows, dramatically increases the probability that the recipient will perceive it as legitimate and take the action that the scammer wants. Kaivanto modifies classical signal detection theory to incorporate psychologically realistic descriptions of perceptions and responses, modeled using Prospect Theory (PT), rather than assuming perfectly rational (expected utility maximizing, System 2) behaviors. Agent-based modeling simulating the responses of networks or organizations of realistically-behaving agents to sustained phishing attacks shows that incorporating PT models of individual responses can significantly affect risk estimates and yield new insights into how best to protect organization from such attacks.
EXPRESSING RISK INFORMATION WITH RISK NUMBERS OR CATEGORIES MacKenzie critically examines the widespread practice of summarizing, comparing, tracking, and communicating risk information using ordered categories or numerical scores (generically called “risk indices”). He identifies flaws in popular risk index methods such as risk matrices, and recommends a constructive procedure for developing sounder and more useful risk indices. This approach distinguishes clearly between risk indices and more demanding quantitative measures of risk, e.g., based on moments, quantiles, utility-based shortfall risk measures, or multifactor models. The procedure is illustrated by constructing risk indices to support comparison of fatality risks across three transportation models: commercial air carriers, on-demand or chartered air taxis/commuters, and highway. Which mode is considered riskiest depends on the underlying risk measure, but air taxis are riskiest by most measures and indices considered. The article not only shows how to move from mathematical
From the Editors measures of risk based on probability distributions to simpler risk indices, e.g., on a scale from 0 to 100, but also emphasizes how clear explanation of the exact meaning and intended interpretation of the resulting numbers—which should accompany every proposed risk index—can help to promote clear thinking and more effective communication between risk analysis practitioners and those who use their results. DOES THE PRECAUTIONARY PRINCIPLE STIFLE SCIENCE AND INNOVATION? Although many have argued that precautionary regulation tends to reduce the role of sound science in regulation, Todt and Luj´an argue that, in principle, precautionary regulation is not necessarily opposed to scientific-technological development, and could even stimulate improvements in scientific method and knowledge, even though, in practice, some applications of precaution may impede scientific analysis and specific innovations. After reviewing controversies over precaution, such as that it may divert resources to speculative hazards or impose opportunity costs that are not properly weighed against benefits, the authors consider ways in which precaution might be based on academic or decision-oriented science. They conclude that precautionary regulation can encourage innovation and may be able to help reconcile the goals of promoting and controlling science and technology. EFFICIENT INSPECTION FOR CERTIFYING ORGANIC PRODUCTS To certify that products marketed as being organic comply with relevant definitions and standards for what constitutes “organic” produce, the European Union relies on costly inspections of conditions on farms. Zanoli et al. consider the statistical challenges that arise in analysis of inspection data over time (farm-level panel data) and discuss the potential for risk-based approaches to noncompliance to improve the efficiency and cost-effectiveness of the certification process. They recommend statistical procedures (e.g., zero-inflated Poisson regression models of count data for slight and severe sanctions) for estimating the probability of non-compliance from predictors such as past compliance history, farm size, and presence of animals on the farm. Weighting this probability by the consequences of noncompliance (as indicated by corresponding sanctions, used as a proxy for severity) yields a risk-based
From the Editors approach to inspection. The authors caution that successful implementation of risk-based inspection strategies is difficult, in part because data on farm and farmer characteristics are limited, and in part because the relations between risk factors and the risks that they predict may change in the future. This issue concludes with a review by Roger Kasperson of the recent book The Risk Society Revisited: Social Theory and Governance, by Eugene Rosa, Ortwin Renn, and Aaron McCright. Kasperson notes that the book helps to fill a persistent void in North American thinking about society and risk, the role of the social sciences in risk analysis and management, and the place of risk in social theory, by drawing on a rich European intellectual tradition of social theory. Kasperson
2065 praises the book highly: “For risk scholars, this is the most coherent and lucid analysis of the contributions and limitations of these important social theorists to risk thinking that can be found in the literature. . . . [It] is the most sophisticated and deep exploration of social theory and its potential role in risk analysis and management available.” Particularly noteworthy is the book’s contribution to thinking about risk governance (as opposed to mere government) and fruitful analytic-deliberative processes in a world of realistic complexity, and uncertainty, where wise risk governance must address overlapping concerns about social justice, inequities, psychological stresses, and conflicts. Tony Cox and Karen Lowrie
