Toward an Epidemiology of Safety and Security Risks: An Organizational Vulnerability Assessment in International Airports

International airports are complex sociotechnical systems that have an intrinsic potential to develop safety and security disruptions. In the absence of appropriate defenses, and when the potential for disruption is neglected, organizational crises can occur and jeopardize aviation services. This investigation examines the ways in which modern international airports can be “authors of their own misfortune” by adopting practices, attitudes, and behaviors that could increase their overall level of vulnerability. A sociotechnical perspective, the macroergonomic approach, is applied in this research to detect the potential organizational determinants of vulnerability in airport operations. Qualitative data nurture the case study on international airports produced by the present research. Findings from this study highlight that systemic weaknesses frequently reside in areas at the intersection of physical, organizational, and social spaces. Specific pathways of vulnerability can be drawn across these areas, involving the following systemic layers: individual, task, tools and technology, environment, and organization. This investigation expands the existing literature on the dynamics that characterize crisis incubation in multiorganization, multistakeholder systems such as international airports and provides practical recommendations for airport managers to improve their capabilities to early detect symptoms of organizational vulnerability.     

An Exploratory Risk Perception Study of Attitudes Toward Homeland Security Systems

Understanding the issues surrounding public acceptance of homeland security systems is important for balancing security needs and potential civil liberties infringements. A psychometric survey was used in an exploratory study of attitudes regarding homeland security systems. Psychometric rating data were obtained from 182 respondents on psychological attributes associated with 12 distinct types of homeland security systems. An inverse relationship was observed for the overall rating attributes of acceptability and risk of civil liberties infringement. Principal components analysis (PCA) yielded a two-factor solution with the rating scale loading pattern suggesting factors of perceived effectiveness and perceived intrusiveness. These factors also showed an inverse relationship. The 12 different homeland security systems showed significantly different scores on the rating scales and PCA factors. Of the 12 systems studied, airport screening, canine detectors, and radiation monitoring at borders were found to be the most acceptable, while email monitoring, data mining, and global positioning satellite (GPS) tracking were found to be least acceptable. Students rated several systems as more effective than professionals, but the overall pattern of results for both types of subjects was similar. The data suggest that risk perception research and the psychometric paradigm are useful approaches for quantifying attitudes regarding homeland security systems and policies and can be used to anticipate potentially significant public acceptance issues.     

Portfolio Analysis of Layered Security Measures

Layered defenses are necessary for protecting the public from terrorist attacks. Designing a system of such defensive measures requires consideration of the interaction of these countermeasures. In this article, we present an analysis of a layered security system within the lower Manhattan area. It shows how portfolios of security measures can be evaluated through portfolio decision analysis. Consideration is given to the total benefits and costs of the system. Portfolio diagrams are created that help communicate alternatives among stakeholders who have differing views on the tradeoffs between security and economic activity.     

Some Criteria for Evaluating Risk Messages

Seven criteria are presented for use in evaluating communications designed to explain the magnitude of a risk. The criteria are: (1) comprehension (Does the audience understand the content of the communication?); (2) agreement (Does the audience agree with the recommendation or interpretation contained in the message?); (3) dose-response consistency (Do people facing a higher dose of a hazard perceive the risk as greater and/or show a greater readiness to take action than people exposed to a lower dose of this hazard?); (4) hazard-response consistency (Do people facing a hazard that is higher in risk perceive the risk as greater and/or show a greater readiness to take action than people exposed to a hazard that is lower in risk?); (5) uniformity (Do audience members exposed to the same level of risk tend to have the same responses to this risk?); (6) audience evaluation (Does the audience judge the message to have been helpful, accurate, clear, etc.?); and (7) types of communication failures (When different types of failures are possible, are the failures that occur generally of the more acceptable variety?). Each of these criteria is illustrated with data collected in a test of message formats designed to explain the risk presented by radon gas in a home.     

The Use of Narrative Evidence and Explicit Likelihood by Decisionmakers Varying in Numeracy

Decisionmakers are often presented with explicit likelihood assessments (e.g., there is a 10% chance that an attack will occur over the next three months) and supporting narrative evidence in forecasting and risk communication domains. Decisionmakers are thought to rely on both numerical and narrative information to the extent that they perceive the information to be diagnostic, accurate, and trustworthy. In two studies, we explored how lay decisionmakers varying in numeracy evaluated and used likelihood assessments and narrative evidence in forecasts. Overall, the less numerate reported higher risk and likelihood perceptions. In simple probabilistic forecasts without narrative evidence, decisionmakers at all levels of numeracy were able to use the stated likelihood information, although risk perceptions of the less numerate were more affected by likelihood format. When a forecast includes narrative evidence, decisionmakers were better able to use stated likelihood in a percentage as compared to frequency or verbal formats. The more numerate used stated likelihood more in their evaluations whereas the less numerate focused more on the narrative evidence. These results have important implications for risk analysts and forecasters who need to report the results of their analyses to decisionmakers. Decisionmakers varying in numerical ability may evaluate forecasts in different ways depending on the types of information they find easiest to evaluate.     

The Dynamics of Risk Perception: How Does Perceived Risk Respond to Risk Events?

This paper examines the relationship between perceived risk and experience. This research addresses the processes by which people learn about risk and choose among real life prospects with associated uncertainties, risks and benefits. By comparing the impact of acute risk events with that of chronic risk events on public perception of risk during and after the events, this research focuses on the learning processes that characterize what kinds of risk events alter the perception of risk. Comparing materialized hazards at existing facilities with the risks associated with potential facilities, this research addresses risk choices among real life prospects. This study uses a classic pre-post quasi-experimental design. Surveys conducted in the Spring of 1992 on perceived and acceptable risk in Odessa and La Porte, Texas were conducted prior to risk events. Respondents from that survey were re-interviewed in the Spring of 1993 after the risk events to form a panel design. This paper analyzes the affect of risk events on perceived risk and the implications of these experiences for public policy concerning technological risk. The empirical results suggest that the social processes that construct and maintain risk in the public eye are at least as important as, if not more important than, the physical and psychological dimensions of risk.     

Perceptions of Randomized Security Schedules

Security of infrastructure is a major concern. Traditional security schedules are unable to provide omnipresent coverage; consequently, adversaries can exploit predictable vulnerabilities to their advantage. Randomized security schedules, which randomly deploy security measures, overcome these limitations, but public perceptions of such schedules have not been examined. In this experiment, participants were asked to make a choice between attending a venue that employed a traditional (i.e., search everyone) or a random (i.e., a probability of being searched) security schedule. The absolute probability of detecting contraband was manipulated (i.e., 1/10, 1/4, 1/2) but equivalent between the two schedule types. In general, participants were indifferent to either security schedule, regardless of the probability of detection. The randomized schedule was deemed more convenient, but the traditional schedule was considered fairer and safer. There were no differences between traditional and random schedule in terms of perceived effectiveness or deterrence. Policy implications for the implementation and utilization of randomized schedules are discussed.     

On Determining Specifications and Selections of Alternative Technologies for Airport Checked-Baggage Security Screening

Federal law mandates that every checked bag at all commercial airports be screened by explosive detection systems (EDS), explosive trace detection systems (ETD), or alternative technologies. These technologies serve as critical components of airport security systems that strive to reduce security risks at both national and global levels. To improve the operational efficiency and airport security, emerging image-based technologies have been developed, such as dual-energy X-ray (DX), backscatter X-ray (BX), and multiview tomography (MVT). These technologies differ widely in purchasing cost, maintenance cost, operating cost, processing rate, and accuracy. Based on a mathematical framework that takes into account all these factors, this article investigates two critical issues for operating screening devices: setting specifications for continuous security responses by different technologies; and selecting technology or combination of technologies for efficient 100% baggage screening. For continuous security responses, specifications or thresholds are used for classifying threat items from nonthreat items. By investigating the setting of specifications on system security responses, this article assesses the risk and cost effectiveness of various technologies for both single-device and two-device systems. The findings provide the best selection of image-based technologies for both single-device and two-device systems. Our study suggests that two-device systems outperform single-device systems in terms of both cost effectiveness and accuracy. The model can be readily extended to evaluate risk and cost effectiveness of multiple-device systems for airport checked-baggage security screening.     

When Precaution Creates Misunderstandings: The Unintended Effects of Precautionary Information on Perceived Risks,the EMF Case

In the past decade, growing public concern about novel technologies with uncertain potential long‐term impacts on the environment and human health has moved risk policies toward a more precautionary approach. Focusing on mobile telephony, the effects of precautionary information on risk perception were analyzed. A pooled multinational experimental study based on a 5 × 2 × 2 factorial design was conducted in nine countries. The first factor refers to whether or not information on different types of precautionary measures was present, the second factor to the framing of the precautionary information, and the third factor to the order in which cell phones and base stations were rated by the study participants. The data analysis on the country level indicates different effects. The main hypothesis that informing about precautionary measures results in increased risk perceptions found only partial support in the data. The effects are weaker, both in terms of the effect size and the frequency of significant effects, across the various precautionary information formats used in the experiment. Nevertheless, our findings do not support the assumption that informing people about implemented precautionary measures will decrease public concerns.     

Evaluating the Efficacy of a Mental Models Approach for Improving Occupational Chemical Risk Protection

Chemical risk protection in the workplace relies partly on informing workers about possible risks using material safety data sheets (MSDS). This article reports on phase 2 of a project (phase 1 reported in Cox et al.), which employed a mental models approach to improve on data sheets as communicative interventions for perchloroethylene in dry cleaning and rosin-based solder flux in the electronics industry within small businesses in the United Kingdom (small enterprises (SEs) < 25 employees in the workplace). It focuses on the efficacy of a multimethod evaluation strategy to assess (1) the capacity of a mental models approach to yield contextually relevant data for intervention design and (2) the effectiveness of the strategy itself in validating the mental models data. The evaluation was conducted using postal questionnaires and semi-structured verbal protocols to provide responses to the alternative intervention content and to prioritize risk messages. User discussion groups were then employed, particularly as a means of establishing whether contextual information could be obtained that would differ qualitatively from the kind elicited through individual (semi) structured methods. We conclude that the mental models approach as part of an iterative process including systematic multimethod evaluation is successful in supporting the design of relevant communications to the users of chemicals. The overall viability of communicative interventions in the context of health and safety in small businesses remains in question. Future research might aim to develop a more holistic approach to interventions in complex occupational contexts.     

Evaluating Risk Communications: Completing and Correcting Mental Models of Hazardous Processes, Part II

We propose a decision-analytic framework, called the mental models approach , for evaluating the impact of risk communications. It employs multiple evaluation methods, including think-aloud protocol analysis, problem solving, and a true-false test that allows respondents to express uncertainty about their answers. The approach is illustrated in empirical comparisons of three brochures about indoor radon.     

Protective Measures,Personal Experience,and the Affective Psychology of Time

We examined the role of time and affect in intentions to purchase a risk‐protective measure (Studies 1 and 2) and explored participant abilities to factor time into the likelihood judgments that presumably underlie such intentions (Study 3). Participants worried more about losing their possessions and were more likely to purchase a protective measure given a longer term lease than a short‐term lease, but only if their belongings were described in affect‐poor terms. If described instead as being particularly special and affect‐rich, participants neglected time and were about equally likely to purchase a risk‐protective measure for shorter and longer term leases. However, and consistent with prior literature, the cognitive mechanism underlying this time‐neglect‐with‐affect‐richness effect seemed to be the greater use of the affect heuristic in the shorter term than the longer term. Study 2 results demonstrated that prior experience with having been burglarized amplified the interactive effect of time and affect. Greater deliberation did not attenuate this effect as hypothesized whether deliberation was measured through numeracy or manipulated through instructions. The results of Study 3 indicated that few participants are able to calculate correctly the risk numbers necessary to take time into account. Two possible solutions to encourage more purchases of protective measures in the long term are discussed.     

The Impact of Joint Responses of Devices in an Airport Security System

In this article, we consider a model for an airport security system in which the declaration of a threat is based on the joint responses of inspection devices. This is in contrast to the typical system in which each check station independently declares a passenger as having a threat or not having a threat. In our framework the declaration of threat/no-threat is based upon the passenger scores at the check stations he/she goes through. To do this we use concepts from classification theory in the field of multivariate statistics analysis and focus on the main objective of minimizing the expected cost of misclassification. The corresponding correct classification and misclassification probabilities can be obtained by using a simulation-based method. After computing the overall false alarm and false clear probabilities, we compare our joint response system with two other independently operated systems. A model that groups passengers in a manner that minimizes the false alarm probability while maintaining the false clear probability within specifications set by a security authority is considered. We also analyze the staffing needs at each check station for such an inspection scheme. An illustrative example is provided along with sensitivity analysis on key model parameters. A discussion is provided on some implementation issues, on the various assumptions made in the analysis, and on potential drawbacks of the approach.     

Evaluating the Simplified Conjoint Expected Risk Model: Comparing the Use of Objective and Subjective Information

The simplified Conjoint Expected Risk (CER) model by Holtgrave and Weber posits that perceived risk is a linear combination of the subjective judgments of the probabilities of harm, benefit, and status quo, and the expected harm and benefit of an activity. It modifies Luce and Weber's original CER model—that uses objective information to evaluate financial gambles—to accommodate activities such as health/technology activities where values of the model variables are subjective. If the simplified model is a valid modification of the original model, its performance should not be sensitive to the use of subjective information. However, because people may evaluate information differently when objective information is provided to them than when they generate information on their own, the performance of the simplified CER model may not be robust to the source of model-variable information. We compared the use of objective and subjective information, and results indicate that the estimates of the simplified CER model parameters and the proportion of variance in risk judgments accounted for by the model are similar under these two conditions. Thus, the simplified CER model is viable with activities for which harm and benefit information is subjective.     

Values,Perceived Risks and Benefits,and Acceptability of Nuclear Energy

We examined how personal values and perceptions of risks and benefits are associated with the acceptability of nuclear energy (NE). A theoretical model is tested in which beliefs about the risks and benefits of NE mediate the relationship between values and acceptability. The results showed that egoistic values are positively related to the perceived benefits and acceptability of NE. In contrast, altruistic and biospheric values were positively related to the perceived risks of NE. Although it has been argued that NE may help to combat climate change through lower CO₂ emissions, these environmental benefits were not acknowledged by people with strong biospheric values. Furthermore, results confirmed that the more risks respondents perceived, the less they were inclined to accept NE. In contrast, the more a person believed that NE has beneficial consequences, the more acceptable NE was. Finally, as expected, perceived risks and benefits were found to partly mediate the relationship between personal values and acceptability. We discuss the theoretical and practical implications of these findings.     

Living Well in Times of Threat: The Importance of Adjustment Processes to Explain Functional Adaptation to Uncertain Security in Expatriates Deployed in the Sudan

The present study investigated expatriate humanitarian aid workers’ perceptions and responses to uncertain security while deployed in the Sudan. Interviews conducted in Khartoum (n = 7) and Darfur (n = 17) focused on risk perception, concern for personal security, and strategies used to function well in an insecure environment. Despite a high perceived general risk, as well as broad knowledge and experience with security incidents, participants often expressed low concern. General adjustment processes were drawn on to explain this finding, while different constellations of processes resulted in different patterns of adjustment. Functional adjustment, resulting in adequate risk perception, protective behavior, protection, and low concern, was characterized by a constellation of complementary activation of accommodation and assimilation processes.     

Psychometric and Demographic Predictors of the Perceived Risk of Terrorist Threats and the Willingness to Pay for Terrorism Risk Management Programs

A 2009 national telephone survey of 924 U.S. adults assessed perceptions of terrorism and homeland security issues. Respondents rated severity of effects, level of understanding, number affected, and likelihood of four terrorist threats: poisoned water supply; explosion of a small nuclear device in a major U.S. city; an airplane attack similar to 9/11; and explosion of a bomb in a building, train, subway, or highway. Respondents rated perceived risk and willingness to pay (WTP) for dealing with each threat. Demographic, attitudinal, and party affiliation data were collected. Respondents rated bomb as highest in perceived risk but gave the highest WTP ratings to nuclear device. For both perceived risk and WTP, psychometric variables were far stronger predictors than were demographic ones. OLS regression analyses using both types of variables to predict perceived risk found only two significant demographic predictors for any threat—Democrat (a negative predictor for bomb) and white male (a significant positive predictor for airline attack). In contrast, among psychometric variables, severity, number affected, and likelihood were predictors of all four threats and level of understanding was a predictor for one. For WTP, education was a negative predictor for three threats; no other demographic variables were significant predictors for any threat. Among psychometric variables, perceived risk and number affected were positive predictors of WTP for all four threats; severity and likelihood were predictors for three; level of understanding was a significant predictor for two.     

Perceived Risk and Benefit of Nuclear Waste Repositories: Four Opinion Clusters

Local public resistance can block the site‐selection process, construction, and operation of nuclear waste repositories. Social science has established that the perception of risks and benefits, trust in authorities, and opinion on nuclear energy play important roles in acceptance. In particular, risk and benefit evaluations seem critical for opinion formation. However, risks and benefits have rarely been studied independently and, most often, the focus has been on the two most salient groups of proponents and opponents. The aim of this exploratory study is to examine the often‐neglected majority of people holding ambivalent or indifferent opinions. We used cluster analysis to examine the sample (N = 500, mailed survey in German‐speaking Switzerland) in terms of patterns of risk and benefit perception. We reveal four significantly different and plausible clusters: one cluster with high‐benefit ratings in favor of a repository and one cluster with high‐risk ratings opposing it; a third cluster shows ambivalence, with high ratings on both risk and benefit scales and moderate opposition, whereas a fourth cluster seems indifferent, rating risks and benefits only moderately compared to the ambivalent cluster. We conclude that a closer look at the often neglected but considerable number of people with ambivalent or indifferent opinions is necessary. Although the extreme factions of the public will most probably not change their opinion, we do not yet know how the opinion of the ambivalent and indifferent clusters might develop over time.     

Expecting the Unexpected: Predicting Physiological and Psychological Wildfire Preparedness from Perceived Risk,Responsibility, and Obstacles

People who live in wildfire‐prone communities tend to form their own hazard‐related expectations, which may influence their willingness to prepare for a fire. Past research has already identified two important expectancy‐based factors associated with people's intentions to prepare for a natural hazard: Perceived risk (i.e., perceived threat likelihood and severity) and perceived protection responsibility. We expanded this research by differentiating the influence of these factors on different types of wildfire preparedness (e.g., preparations for evacuation vs. for defending the house) and measured actual rather than intended preparedness. In addition, we tested the relation between preparedness and two additional threat‐related expectations: the expectation that one can rely on an official warning and the expectation of encountering obstacles (e.g., the loss of utilities) during a fire. A survey completed by 1,003 residents of wildfire‐prone areas in Perth, Australia, revealed that perceived risk (especially risk severity) and perceived protection responsibility were both positively associated with all types of preparedness, but the latter did not significantly predict preparedness after controlling for other predictors and demographics. Also, the two new expectancy‐based factors were significantly associated with all types of preparedness, and remained significant predictors of some types of preparedness after controlling for other predictors and demographics: the expectation of being able to rely on an official fire warning and expecting to lose electricity both still predicted less preparedness around house resilience, and expecting to lose water still predicted increased planning preparedness. We discuss public policy implications that follow from this research.