Influence of Information Delivery on Risk Ranking by Lay People

Overview

Practitioners and researchers alike are presented with choices regarding how risk information should be presented, especially when these issues are of central importance to the audience (i.e., environment, health, personal safety).  Often it is necessary to present complex risk information in a comprehensible manner.  In order to increase comprehension decision makers who inform the public must consider how their audience is likely to take in the risk information and create their own opinions.  Therefore, it is important to both inform the public of risk information, but also to do it in such a way that the risk information affects public attitudes and behavior in a desirable way. 

Purpose

Most of the research done today on the ranking of risk perceptions has been done in developed countries.  The current study extends the ranking of risk perception research to developing countries, in particular, Chile.  Socioeconomic and cultural differences may influence how risk information is received at the individual level.  The current study seeks to uncover those differences that may make the applicability and generalizabiliy of current research inappropriate.

Hypotheses

H1: The quantity and type of information provided does have a bearing on risk ranking.
H2: Providing lay people with further information – characteristic of the hazard (attribute) -results in better agreement.
H3: Narrative information (which may cover previously held beliefs) is more important than attribute information.
H4: When only presented with attribute data, people not told the name of the risk base their rankings on just one attribute: the expected number of deaths.

Method

The authors conducted the risk-ranking experiments in a low- to middle-income borough in Santiago, Chile.  Participants ranked the hazards they are exposed to within their borough, according to their level of concern.  The authors identified twelve risks relevant to the population: suspended particulate matter (air pollution), illicit drug consumption, air plane crashes, car crashes, electromagnetic fields (EMFs), nuclear reactor accidents, transport of hazardous materials, floods, obesity, HIV, and earthquakes. 

A descriptive paragraph which briefly summarizes all important information about the risk was created for each risk.  An attribute table was also created that contained simplified data regarding each risk.  The eight attributes addressed were: greatest expected number of deaths in a single episode, personal capability of controlling exposure to a risk episode, mortality rates per 100,000 people, expert knowledge of the consequences of the risk, time lag from exposure to awareness of effects, expected number of deaths and injuries/illnesses

Four survey formats were used in order to test the hypotheses: paragraph (descriptive of hazard), paragraph plus attribute table, full brochure (longer description), unlabeled table (risks were given letters and not names to hide their true labels). 

Participants were randomly given one of the four formats, and were asked to rank the risks consistent with their own personal concerns.  Next they were asked to evaluate different aspects of the procedure and their rankings. 

Results & Discussion

Format four (unlabeled table) was ranked as both the most difficult yet also the most satisfying format to use.  Two possible explanations for this are: (1) people are more satisfied after finishing a task they find difficult, or (2) the inherent difficulty of thinking about multiple attributes is high, so people would tend to focus on just one attribute (expected deaths) that makes the task easier and at the same time appear more objective. 

When the average rankings for formats 1, 2, and 3 are examined together the authors found that the amount of information delivered has no effect.  For the other risks differences among all three formats are minor.  Rankings also indicate that the expected deaths are the most important attribute when risk is unlabeled.  Finally, the results show that the amount of information, and the way it is delivered, may affect how lay people rank risks, but not to a great extent.

Authors' Biographies

Virna Vaneza Gutiérrez Gianella

A native of Santa Cruz, Bolivia, Professor Gutierrez attended University Diego Portales for her undergraduate studies in Industrial Engineering in 1999. In 2005, she obtained  M.Sc in Engineering Sciences at Pontificia Universidad Católica de Chile. Professor Gutierrez works at Universidad Diego Portales in the School of Industrial Engineering, Chile. Her research areas and interests include multivariate analysis for social science, risk perception, communication and ranking. She is currently conducting research in the relations of social trust, acceptability and level of compensation of environmental risk in a less developed country. Professor Gutiérrez have worked for the Ministry of Transportation an Telecommunication in Bolivia and has been a consultant for The Ministry of Public Work (MOP) and Ministry of Education (MINEDUC) in Chile.

Luis Abdón Cifuentes Lira

Dr. Cifuentes is associate professor at the Industrial and Systems Engineering Department, and head of the Center for Environment of the Pontifical Catholic University of Chile. He received his undergraduate degree in Civil Engineering from the Catholic University of Chile in 1982.  In 1986 he obtained  a M.Sc. in Civil Engineering as a Fulbright scholar, and in 1995 he received a Ph.D in Engineering and Public Policy from Carnegie Mellon University.  He has been a professor at the School of Engineering since graduation, where he teaches Environmental Management, Environmental Economics and Risk Analysis.

His research interests include the co-benefits of climate change mitigation, the social impacts of air pollution and climate change and risk analysis and perception. Dr. Cifuentes has been a consultant for several organizations, including the National Environmental Commission of Chile, the US Environmental Protection Agency’s (EPA) Integrated Environmental Strategies program, and for the Inter-American Development Bank. He has participated as Lead Author of the Co-benefits of climate change section for the Third and Fourth Assessment reports of the Intergovernmental Panel on Climate Change. In 2002 he received the Climate Protection award from the US EPA for his work in co-benefits of climate change mitigation.

Nicolás Bronfman Cáceres

Professor Bronfman works at Universidad Nacional Andrés Bello as a head of the Department of Engineering Sciences. His research areas are in the field of risk perception, risk communication, quantitative risk analysis and risk assessment. Professor Bronfman has a Doctoral degree in Engineering Sciences at Pontificia Universidad Católica de Chile (2005). He is currently working in subjects related to industrial process quantitative risk analysis, acceptable risk criteria, social trust in risk management institutions, and risk perception and communication.

Know of an article that should have our spotlight? Send nominations to riskcenter@umd.edu.