public support for earthquake risk mitigation in portland, oregon

Risk Analysis, Vol. 19, No. 2, 1999

Public Support For Earthquake Risk Mitigation InPortland, Oregon

James Flynn,1,3 Paul Slovic,1 C. K. Mertz,1 and Cathie Carlisle2

During the 1980s, seismic research suggested that Oregon and the City of Portland had ahigher risk of a major earthquake than had previously been assumed. In 1993, the State ofOregon adopted a new version of the Oregon Structural Specialty Code, which changed thedesignation of western Oregon from seismic zone 2b to seismic zone 3. The City of Portlandestablished a program and a Task Force on Seismic Strengthening of Buildings to recommendactions that would encourage upgrading of city buildings. A survey of adult city residentswas conducted in April, 1996 to determine public attitudes and opinions about earthquakerisks, management and mitigation of earthquake hazards, priorities for protection by strength-ening buildings, evaluations of strategies for informing the public about earthquake risks,and support for specific options the city might take to protect citizens against earthquakeevents. Social and demographic information on individuals and households was also collected.Respondents provided ratings for a wide range of social and environmental risks, providedinformation on priorities for strengthening key buildings and infrastructure facilities, andanswered hypothetical questions about voting for bond measures to pay for city earthquake-mitigation programs. Respondents recognized significant risk from earthquakes and sup-ported programs to protect people, especially vulnerable residents such as children and thesick. There was strong support for protecting emergency response capabilities. There wasmuch less support for using public funds to reduce the risks associated with privately ownedbuildings. There were also some strong pockets of resistance to publicly funded mitigationprograms in response to the hypothetical bond measures.

KEY WORDS: Seismic risk; risk perceptions; earthquake hazards; risk mitigation.

1. INTRODUCTION

The potential for loss of life, injury, and damageassociated with earthquakes, or seismic risk, has beenwell documented. The recent Loma Prieta and North-ridge earthquakes in California and the earthquakein Kobe, Japan provided grim evidence of what canhappen when earthquakes strike near metropolitan

1 Decision Research, 1201 Oak Street, Eugene, Oregon 97401-3575.

2 The City of Portland, Oregon, Bureau of Buildings, 1120 S. W.5th Avenue, P. O. Box 8120, Portland, Oregon 97204-1992.

3 To whom all correspondence should be sent.

2050272-4332/99/0400-0205$16.00/1 1999 Society for Risk Analysis

areas. More than 5000 people were killed in the Janu-ary 15, 1995 Kobe earthquake. The January 17, 1994Northridge earthquake has been billed as the mostexpensive disaster in U.S. history with losses esti-mated at $24 billion, and possibly as much as $40billion.(1) These events were widely broadcast by thenews media and presented in dramatic televisionstories.

Better information about losses associated withearthquakes has prompted new strategic planningand risk management efforts throughout the country,especially in California and other western states thatare considered vulnerable to seismic hazards.(2) Theseefforts include the development of public information

206 Flynn, Slovic, Mertz, and Carlisle

campaigns and emergency plans, increases in seismicdesign standards for new buildings, and the adoptionof regulations requiring existing buildings and otherinfrastructure to better resist earthquake groundshaking. The latter of these strategies has generatedthe most controversy.

Although the failure of existing buildings andother structures constitutes the primary risk to lifeand safety during earthquakes,(3) including dangersfrom releases of hazardous materials,(4) proposals forrequiring the strengthening of existing buildings andinfrastructure often meet with significant opposition.The high financial costs associated with seismic up-grades can generate strong political resistance fromtaxpayers, building owners, and other constituentgroups who believe that they will be negatively im-pacted by more stringent regulations. Other publicpolicy goals can come into conflict with attempts toimprove seismic safety. For example, several cities inCalifornia that adopted mandatory seismic upgraderequirements for unreinforced masonry buildingswere faced with a dilemma because many of thesebuildings provide space for affordable housing indowntown areas.(5) Does improving the seismic safetyof buildings justify the loss of affordable housingspace? The answer to this question is likely to elicitvarying responses, depending on the perspective ofthe respondent.

If seismic upgrade requirements are adopted,taxpayers and residents may eventually be asked tobear the costs, even for privately owned buildings.Owners of apartments and commercial buildings willattempt to transfer the costs of upgrading their build-ings to tenants and customers. In addition, govern-ments will spend tax dollars to initiate and operateseismic mitigation programs as well as spending tostrengthen publicly owned buildings. Depending onthe community’s economic circumstances, seismic re-quirements may eventually lead to demolitions andbuilding abandonment, altering the community’s ar-chitectural and social environment. On the otherhand, should an earthquake occur, a decision to nottake action could also be costly in terms of lives lostand property damaged. Practically, some compro-mise between the maximum technically possible stan-dards of seismic strengthening and a cost-effectivecompromise must be reached. In this context, publicsupport for any new policy and programs is critical.

The possibility that major structural changes toachieve seismic strengthening would be highly visibleto members of the public and might affect the atti-tudes and opinions of community residents toward

specific properties or sections of the communityshould be taken into account prior to adopting newpolicies. The range of information that applies tothese situations is quite broad. For example, how docommunity residents perceive seismic risks? How dothey view various policy options for reducing the riskfrom earthquakes in their communities? What arethey willing to pay to reduce these risks? Do residentswho oppose risk reduction measures differ in somesignificant way from those who support these poli-cies? An examination of citizen attitudes towardearthquake risk reduction actions in the context oftheir perception of the earthquake risk should assistpolicy makers in obtaining public support and design-ing an effective risk management and informationprogram.

One way to obtain information on these ques-tions is to conduct a public sample survey. Accord-ingly, the present authors designed and analyzed sucha survey. Seismic risk surveys have been conductedpreviously by Palm and Hodgson,(6) Field and Dicam-illo,(7) Alesch and Petak,(8) and Garcia and Pontell(9)

in California, a state with a long history of earthquakeactivities near population centers and extensiveearthquake-mitigation programs.(4) Questions inthese surveys were reviewed and additional questionswere developed to meet the objectives of the Port-land Task Force an the Seismic Strengthening of Ex-isting Buildings (the Task Force), which wanted thesurvey to address public attitudes and opinions aboutthe policy issues related to the changes in the buildingcode, potential options for the seismic strengtheningof existing buildings, and recommendations to theCity Council.

2. PORTLAND CODE BACKGROUND

In the Uniform Building Codes, seismic designrequirements are generally determined by the earth-quake zone designation that applies to a particulargeographic area. Earthquakes were not consideredin Portland’s building code at all until 1956, and atthat time, city officials chose not to adopt the zonethat was recommended for the area. In 1974, theOregon Legislature adopted a state-wide buildingcode, with the recommended seismic zone and allnew buildings in Oregon had to comply with thestate standards. During the 1980s, seismic researchsuggested that Oregon and the City of Portland had ahigher risk of a major earthquake than had previouslybeen assumed.

Public Support for Earthquake Risk Mitigation 207

In response to the increasing consensus amonggeologists that Oregon may be more susceptible toearthquakes than was previously believed, the Ore-gon Building Codes Division adopted a higher seis-mic zone for the state in 1990. In 1993, the Stateof Oregon Building Codes Division adopted a newversion of the Oregon Structural Specialty Code,which changed the designation of western Oregonfrom seismic zone 2b to seismic zone 3. This revisionincreased the requirement for minimum design seis-mic loads to 50 percent over the 1990 code. ThePortland Dangerous Building Code specifies thatbuildings unable to carry or sustain 66 percent of allloads or forces required by the current building codebe considered dangerous and, as such, be either im-proved to comply with current code or be demol-ished. With adoption of the 1993 code,(10) ‘‘even rela-tively new buildings could be considered dangerousbuildings by definition’’ (pp 6–8).

Further, because many of Portland’s older ex-isting buildings were not designed with earthquakesin mind at all, they are especially vulnerable to earth-quake ground shaking. For example, many of Port-land’s older buildings are constructed of unreinforcedmasonry bearing walls that contain insufficient, if any,seismic reinforcement. These kinds of buildings haveperformed poorly in past earthquakes, includingearthquakes of small to moderate magnitude, andstructural engineers consider them to be a seriousthreat to public safety.

To address the issues arising from the new earth-quake data and subsequent building code changes,the Portland City Council appointed the Task Forceon the Seismic Strengthening of Existing Buildings.Members of the Task Force represented buildingowners, managers of education and health-care facili-ties, banking, law, architecture, structural engi-neering, and affordable housing. To resolve the city’sdangerous building code problem, the Task Forcerecommended that the code should be amended sothat seismic strength requirements do not apply tothe definition of ‘‘dangerous structures.’’ The TaskForce was then charged with researching and devel-oping program options for the strengthening of ex-isting buildings in Portland.

This survey was implemented by the City ofPortland, Bureau of Buildings, in close cooperationwith the Task Force, to better understand city resi-dents’ attitudes toward earthquake risks and actionsto mitigate those risks. To design and conduct thesurvey, the City of Portland first hired Moore Infor-mation, a Portland survey firm, and then added Deci-

sion Research, a nonprofit research group from Eu-gene, Oregon.

3. SURVEY DESIGN

The survey was designed by Moore Informationand Decision Research with review and input by acommittee from the Task Force. The target popula-tion was adult, English-speaking residents of Portlandliving in households with telephones. The survey in-strument was structured to obtain attitudes towardearthquake risks, perspectives on management andmitigation of earthquake hazards, priorities for pro-tection by strengthening buildings, evaluations ofstrategies for informing the public about earthquakerisks, support for specified strategies to inform thepublic about earthquake risks, and support for certainoptions the City of Portland might have in fundingearthquake-mitigation programs. Additional ques-tions were included to obtain social and demographicinformation on individuals and households.

4. SURVEY IMPLEMENTATION

The sampling and data collection tasks were per-formed by Moore Information. Moore Informationselected respondents from the current U.S. WestTelephone Directory for Portland, Oregon. The in-terviews were conducted on April 13 and betweenApril 18 and 21, 1996. A total of 400 interviews werecompleted. The expected margin of error for a samplesize of 400 respondents is 5 percent at the 95 percentconfidence level. Moore Information provided a de-scription of their sampling and data-collection proce-dures in a memorandum to Decision Research datedMay 17, 1996. Based on this account, we calculatedthat the response rate for the survey was 23.7 percent,which should be considered low. Given the samplingand the response rate, these data should be used withcaution in generalizing to the population of Portland.With this caution in mind, we believe that the datado provide insight into the nature of perceptions andattitudes toward earthquake risks on the part of therespondents and may indicate responses on the partof city residents to potential mitigation policies.


5. SURVEY FINDINGS

5.1. Perceptions of Earthquake Risks

Risk involves a threat of injury, damage, or lossand risk management involves an attempt, systematicor otherwise, to reduce or eliminate the probabilityand/or the consequences of a hazardous condition.For example, an extremely dangerous material suchas highly radioactive spent fuel from a nuclear powerreactor may be considered an acceptable conse-quence of electric generation if the management ofsuch wastes is effective and there is almost no possi-bility of dangerous exposure to humans or the envi-ronment. The categories of probability and conse-quences are often used to summarize risk and providequantified data for risk assessments. However, thesesummaries tend to understate the complex factorsthat human beings bring to their evaluations of risk.Understanding more of the social, cultural, psycho-logical, and ethical factors involved in risk evalua-tions is important to communicating and gaining sup-port for programs or projects to mitigate risk. Thebroad array of considerations that contribute to pub-lic perceptions of risk include the dread people haveof different consequences, how well they believe thatthe hazard and its consequences are understood,whether the risk is voluntary or involuntary for thosepeople most effected, the trust and confidence in riskmanagers, their familiarity with the risks, and thepotential costs and benefits of accepting the risk. Re-sponses to natural hazards typically evoke less con-cern than man-made hazards such as those producedby chemical, nuclear, or other highly technical pro-cesses.

In this survey, people were asked to rate differ-ent kinds of hazards to provide a context for theirevaluations of earthquakes. Such ratings for individu-als and their families are moderated by the specificcircumstances that apply for each respondent. In thiscontext, the list reminds the respondent that peopleface a variety of risks in their everyday lives. Socialrisk items were included in the form of questionsabout public safety such as fire, crime and violence,drinking alcohol, and using street drugs. Respondentswere asked about health and safety risks such as thoseassociated with cancer, medical x-rays, and AIDS.Transportation risks included operating motor vehi-cles and using commercial air transport. In the realmof technology, respondents were asked to evaluatenuclear power plants, electromagnetic fields frompower lines, and large dams. For natural hazards,

people were asked about windstorms, flooding, andearthquakes. These hazards exhibit a wide range ofthe characteristics that researchers have found to beimportant to differential perceptions of risk. Respon-dents were asked to provide a rating for each riskitem on a scale from ‘‘little or no risk’’ to ‘‘high risk.’’These ratings were scored from 1 to 4 with the highestnumber assigned to ‘‘high risk.’’ Figure 1 shows themean scores for these risks. The directions for thisset of ratings asked the respondents to think aboutthe risk ‘‘to you and your family.’’ Higher ratings areusually obtained when people are asked for a ratingof risks for larger social units, such as the city, state,or country.

Earthquakes ranked fifth on the 15-item list, thehighest rated of the natural hazards, ahead of wind-storms and flooding. This indicates that earthquakesare viewed as an important risk in comparison toother risks. In addition, the ratings are also importantto individual decision processes. Perceptions of riskhave been shown to influence people’s willingness tosupport programs of risk reduction and miti-gation.(11–14)

In addition to this comparative rating, twoadditional questions were asked about the perceivedprobability of an earthquake (Table I). One ques-tion asked about the likelihood of a major earth-quake in the Portland area during the next 10years, and a second question asked about the likeli-hood that a major earthquake would occur duringtheir lifetime. A strong majority of the respondents(62.5 percent) thought a major earthquake waslikely or very likely in the next 10 years and 80.3percent thought that such an event was likely orvery likely within their lifetime.

The ratings of earthquake risk were combinedto form an Earthquake Risk Index. This index, andanother index (Risk Index) that was the mean ofthe ratings of all the other risks (questions 1–9and 11–15) were then used as independent variablesto assess the relationship of risk perceptions tosupport for a number of policy and program optionsdesigned to mitigate earthquake risks, as discussedin Section 5.7.

5.2. Information About Earthquake Risk

Having information about a specific risk has of-ten been cited as important for informed decision-making.(15) Measuring the adequacy of a person’s riskknowledge is a complicated process not easily done


Fig. 1. Perceptions of risks for social and environmental conditions.

in a short telephone survey. Therefore, as a shortcut,respondents were simply asked to rate their own levelof information by agreeing or disagreeing with astatement saying they were well-informed aboutearthquake risks in Portland (Table II). More thantwo-thirds of the respondents said they strongly orsomewhat agree with this characterization of theirknowledge level. In terms of earthquake prediction,more than half (52.8 percent) of the respondents wereskeptical about the ability of scientists to predict

Table I. Judgments About the Likelihood of Earthquakes Occurring in the Portland Area (n � 400)

VeryVery Likely Unlikely unlikely Don’t

likely (%) (%) (%) (%) know (%)

How likely do you think it is that a major earthquake will occur 16.0 46.5 28.3 7.5 1.8some time in the next ten years in the Portland area?

Thinking about the longer term, how likely do you think it is 33.3 47.0 13.0 4.5 2.3that there will be a major earthquake in the Portland areawithin your lifetime?

Note. Percentages may not total 100 percent due to rounding.

when and where a serious earthquake might occur.Just over half (51.8 percent) thought they had somecontrol over their exposure to earthquake hazards,and slightly less than half (46.8 percent) said they didnot think there was much they could do about anearthquake as individuals. In terms of the communityability to control earthquake impacts there was muchgreater confidence. Three-quarters of the respon-dents (74.8 percent) thought the city could lessenearthquake effects. However, 73.3 percent of the sur-


Table II. Information and Knowledge About Earthquake Risks (n � 400)

SomewhatStrongly Somewhat disagree Strongly Don’t

agree (%) agree (%) (%) agree (%) know (%)

I consider myself to be well-informed about earthquake 33.3 34.5 25.0 5.8 1.5risks in Portland.

If an earthquake is going to harm me it will, and there 22.8 24.0 28.8 23.0 1.5isn’t much I can do about it; what will be, will be.

If an earthquake is going to occur, there is not much my 6.8 13.0 26.5 48.3 5.5city or community can do to lessen its effects.

If there is a really serious threat from an earthquake in 7.3 16.3 36.3 37.0 3.3the Portland area, city officials will announce it. Untilthey alert me about such a problem, I don’t really haveto worry.

I am skeptical of the ability of scientists to predict where 25.0 27.8 30.3 14.0 3.0and when a serious earthquake will occur.


vey respondents somewhat or strongly disagreed withthe statement that they would not worry about earth-quake risk and they could count on the city to tellthem if there was a problem.

5.3. Evaluations of Potential Support for CityActions

A set of four questions asked for support oropposition to possible actions by the City of Portlandto reduce the risk of earthquakes (Table III). Eachitem was briefly described and combined with a re-minder that it could require an increase in taxes. Noestimates were made for the costs and the possibletax increase. Two programs got strong support. Thesuggestion that the city provide ‘‘better public earth-

Table III. Support for Possible City of Portland Actions To Reduce Earthquake Risks (n � 400)

Strongly Somewhat Somewhat Stronglysupport support oppose oppose Don’t

(%) (%) (%) (%) know (%)

Mandatory strengthening of existing government buildings, 24.5 31.0 21.5 16.8 6.3even if this means an increase in taxes.

Mandatory strengthening of existing privately owned buildings, 16.5 28.5 26.0 21.8 7.3excluding private houses, even if this means increased coststo owners, users, and their customers.

Better public earthquake information programs, even if this 43.5 28.5 16.0 8.8 3.3means an increase in taxes.

Better community emergency preparedness, even if this means 45.8 31.3 11.8 7.8 3.5an increase in taxes.


quake information programs’’ was supported by 72.0percent of the respondents, with 43.5 percent sayingthey strongly supported the idea. A program to pro-vide ‘‘better community emergency preparedness’’did even better; 77.1 percent supported this idea,with 45.8 percent strongly in support. A program torequire ‘‘strengthening of existing government build-ings’’ received 55.5 percent support, with 24.5 percentsaying they were strong in their support. The ‘‘man-datory strengthening of privately owned buildings’’obtained 45.0 percent support (16.5 percent strongsupport) and slightly more respondents (47.8) per-cent opposed this idea, with 21.8 percent saying theywere strongly opposed. These items were used asdependent variables in a multivariate analysis, whichwas designed to understand who supported the vari-ous potential earthquake-mitigation programs andwhy (see Section 5.7).


5.4. Priorities for Protecting People and Property

The most significant threat to people during amajor earthquake comes from the failure of buildingsand other structures. The costs of retrofitting build-ings is considerably greater than the cost of designingto earthquake protection standards during the origi-nal construction period. Our society now seems tobe in a period where public expenditures are carefullyexamined and tax resources are limited. This meansthat public programs to strengthen existing buildingsand public infrastructure (e.g., bridges, roads, andpublic utilities) will have to command a high prior-ity rating.

A series of questions asked respondents to assigna rating on a scale of 1 to 10 for specified buildingsand infrastructure facilities where 1 means no moneyshould be spent to strengthen the facility and 10means it is absolutely essential to spend money tostrengthen the facility. The mean ratings for 16 build-ings and structures are shown in Fig. 2. These re-sponses substantiate the evaluations shown in Section5.3. The emphasis on protecting hospitals and emer-gency communications, ranked numbers one and

Fig. 2. Priority ratings for strengthening key buildings and infra-structure facilities.

three on the support ratings, reflect the prioritiesgiven to better community emergency preparedness.Protection against the possible release of hazardouswastes was rated second on the list, with 50.3 percentsaying that it is ‘‘absolutely essential to spend moneyto strengthen’’ to mitigate this class of hazards. Thecombination of hazardous wastes and an earthquakeapparently produces a compound risk and a highpriority rating.(3)

The ambiguity respondents expressed towardsupporting strengthening of privately owned build-ings is shown in the ratings for the bottom four itemsin Figure 2, where high-rise buildings, apartmentbuildings, office and retail buildings, and arenas andstadiums are accorded the lowest priorities. Althougharenas and stadiums are not all privately owned, someare, audiences are present at events in these facilitiesfor a relatively short time, and by their own choice.

The priority ratings of these specific items wasfollowed in the survey with two questions that askedthe respondents to make a value-based priority judg-ment. People were asked to choose the first priorityfrom among three classes of buildings: (1) buildingswith the greatest number of people at risk; (2) build-ings where especially vulnerable people, such as chil-dren and the sick were at risk; and (3) buildings mostlikely to fail in an earthquake regardless of who wasat risk (Table IV). After the first choice from thesethree options was made, the respondents were askedfor their second choice. The responses show thatthese are not easy trade-off judgments. On the firstround, almost one-quarter (23.7 percent) selecteditem 1, to strengthen buildings with the greatest num-ber of people, and over one-third (38.4 percent) se-lected item 2, to strengthen buildings with specialpopulations, such as children and the sick. Almostas many people selected item 3, to strengthen theweakest buildings (37.9 percent). On the secondround (question 44) the distribution was: 39.5 percentselecting item 1; 38.9 percent selecting item 2, and21.5 percent selecting item 3. After both choices wererecorded, item 2 (protection for special and vulnera-ble populations) had the most support, with strongsupport for protecting the buildings with the greatestnumber of people. There is some overlap in meaningbetween items 1 and 3, although item 1 focuses onthe number of people at risk and item 3 focuses onthe buildings. In terms of the thinking about riskas a combination of probability times consequences,however, the total potential damage may be consid-ered to be fairly equal. That is, weaker buildings mayhave a greater proportion of casualties and the total


Table IV. Ratings of Priorities for Strengthening Buildings (n � 354)

First Priority (Q43)

Greatest Special Weakest Totalnumber of populations buildings second

Second priority (Q44) people (%) (%) (%) priority (%)

Greatest number of people 0.5 22.0 16.9 39.5Special populations 17.2 1.1 20.6 38.9Weakest buildings 5.9 15.3 0.3 21.5Total first priority 23.7 38.4 37.9 100.0

Note. People who did not answer, did not know their preference, or for other reasons didnot provide a response to one or both questions were deleted from this table (n � 46).Percentages may not total 100 percent due to rounding.

risk may be equal to buildings which contain alarger population.

5.5. Informing the Respondents and Asking AboutSupport

Respondents were provided information aboutincreases in earthquake risk estimates and the re-sulting changes in local construction requirementsfor new buildings and buildings that have a change inuse or are remodeled. Respondents were then askedwhether they supported city efforts to upgrade ex-isting buildings. The responses provided a strong en-dorsement, with 71.8 percent saying they either sup-ported (39.3 percent) or strongly supported (32.5percent) city efforts.

5.6. Support for City of Portland EarthquakePrograms

A set of three questions were asked, pertainingto a hypothetical vote on bonds to fund city effortsand mitigate earthquake risk. Respondents were firstasked if they were registered voters, with almost 80percent saying they were. Those who were registeredvoters were then asked to say if they were for oragainst a hypothetical bond issue that would cost theowner of a $150,000 house about $19 a year. Thebond was described as one to fund the strengtheningof public buildings. A strong majority (75.2 percent)said they would vote for this level of public funding

(Table V). The people who said they would voteagainst this bond proposal or said they did not knowhow they would vote (79 respondents), were thenasked how they would vote on a reduced bond, atan annual cost of $9 for a $150,000 house, tostrengthen only police and fire facilities. A quarterof this subgroup of respondents (24.1 percent) saidthey would vote for the lower-cost bond, whereas64.6 percent said they would vote against it, and 11.3percent did not know how they would vote. The 51people who opposed a bond issue at both levels ofcost made up 16.0 percent of the 319 respondentswho identified themselves as registered voters. Thefinal substantive questions asked about public finan-cial support for private owners and citizens affectedby city efforts to strengthen buildings and reduceearthquake risk. Respondents were evenly split onthe question of public assistance to private propertyowners; 45.8 percent were opposed and 48.3 percentwere in favor (with 6.0 percent undecided). On thequestion of financial assistance for elderly and lowincome renters whose rents would be increased bycity programs to strengthen buildings, 75.3 percentfavored such assistance.

A formal engineering examination of buildings,which would be required for any comprehensive pro-gram of earthquake mitigation, would produce infor-mation about the vulnerability of specific buildings.This information, in turn, could reduce the attrac-tiveness of a building rated as at a relatively highrisk during an earthquake. Respondents were askedwhich of two options they preferred for handlingthis public information. Half the respondents (49.8percent) said the information ‘‘should be publishedor displayed even if this means some people mightavoid certain businesses or buildings,’’ while 36.0 per-


Table V. Percent Support for City of Portland Earthquake Programs

Definitely Probably Lean Probably Definitely Don’tfor for Lean for against against against know

Registered voters(n � 319): Vote for or against bond at aver- 26.7 43.3 5.3 2.2 6.6 11.9 4.1

age household cost of $19 year.If don’t know/against on above question(n � 79): Vote for or against bond at average 6.3 13.9 3.8 7.6 25.3 31.6 11.4

household cost of $9 year.

Strongly Strongly Don’tn � 400 support Support Oppose oppose know

Support public financial assistance programs for private building owners. 16.8 31.5 20.8 25.0 6.0Support special city programs to hold down the cost of housing for 41.3 34.0 11.8 8.0 5.0

affected low-income residents.


cent said the information should be ‘‘available whensomeone asks for it,’’ and 14.3 percent did not knowwhich of the two options would be best. Given that14.3 percent of the respondents answered ‘‘don’tknow’’ and the fact that only half supported activedisclosure of the information, it appears that this isa difficult ethical problem involving the propertyrights of building owners and the level of access thecity should provide to this information.

5.7. Further Analyses

This section describes findings resulting fromanalyses of the survey data to address some issues ofspecial interest. Table VI shows regression analysisresults for six dependent variables. The dominantfinding was that people with higher earthquake riskperceptions (Earthquake Risk Index) are more sup-portive of all the mitigation programs (questions 23–26, 47, and 48), including support for bond measures.Respondents also supported the idea that the citycould exercise some control over earthquake effects.Among those who disagreed with the statement thatthere was not much the city could do to lessen theeffects of earthquakes (question 20), there was sup-port for mandatory strengthening of governmentbuildings (p � .05), earthquake information pro-grams, emergency preparedness, and for the higherlevel of bond funding (p � .01).

In terms of sociodemographic characteristics, fe-male respondents were more likely to support man-datory strengthening of government buildings, aswere more recent residents to Oregon (p � .05).Other sociodemographic variables—education, age,

income, and self-rated level of knowledge—did notsignificantly predict any of the dependent variables.

A further analysis of the sociodemographic vari-ables looked at subgroups and the votes for andagainst the $19 per year bond issue. Only those re-spondents who said they were registered voters wereasked how they would vote on the bond issue (n �319). The outcomes of these votes are shown in TableVII for age (p � .05), home ownership (p � .01),education (not significant), and household income(p � .01).

People over age 55, those who own their homesrather than renting, and those with the highest re-ported household incomes (over $75,000) recordedmore opposition to the bond issue than did otherrespondents. Notice, however, that the opposite pat-tern also occurred for education, where there was aninverse relationship between education and support.However, the relationship between education andvotes on the bond was not statistically significant.

An examination was done of the geographicallocation of respondents and opposition to the $19per year bond proposal. Question 63 identified re-spondents in four areas of the city, percentage ofresponses against the bond issue were: West Side(13.6 percent opposed); North Side (16.2 percent op-posed); Near East Side (14.4 percent opposed), andthe Far East Side (29.3 percent opposed). Oppositionfrom the Far East Side was about twice that recordedfor the other areas. This may be due to the fact thatthe Far East Side is separated from the downtownby the Willamette River and there are fewer physicalconnections and less affective identification withearthquake risks that apply most strongly to thedowntown buildings.


Table VI. Multivariate Analysis of Key Independent and Dependent Variables: Standardized Regression Coefficients

Man

dato

ryst

reng

then

ing

ofgo

vern

men

tbu

ildin

gs(Q

23)

Man

dant

ory

stre

ngth

enin

gof

priv

ate

build

ings

(Q24

)

Bet

ter

publ

icea

rthq

uake

Info

rmat

ion

Pro

gram

s(Q

25)

Bet

ter

com

mun

ity

emer

genc

ypr

epar

edne

ss(Q

26)

Vot

efo

r$1

9/ye

arbo

ndm

easu

re(Q

47)

Vot

efo

r$9

/yea

rbo

ndm

easu

re(Q

48)

Independent variables

Earthquake risk index �.23a �.21b �.20b �.16b �.21b �.43c

Risk index �.02 �.06 �.04 �.07 �.03 �.31I consider myself to be well-informed about earth- �.03 �.02 �.01 �.08 �.08 �.16

quake risks in Portland (Q18).If an earthquake is going to harm me it will, and �.11 �.12 �.02 �.03 �.02 �.23

there isn’t much I can do about it; what will be,will be (Q19).

If an earthquake is going to occur, there is not much �.13c �.12 �.19b �.19b �.18b �.15my city or community can do to lessen its effects(Q20).

If there is a really serious threat from an earthquake �.07 �.01 �.05 �.07 �.06 �.03in the Portland area, city officials will announce it.Until they alert me about such a problem, I don’treally have to worry (Q21).

I am skeptical of the ability of scientists to predict �.02 .00 .00 �.03 �.10 �.29where and when a serious earthquake will occur(Q22).

Registered voter in Portland (1 � yes; 2 � no) �.02 �.01 �.05 �.08 N/A N/A(Q46).

Age �.12 �.03 �.01 �.02 �.06 �.06Education �.07 �.07 �.10 �.04 �.06 �.28Income �.04 �.10 �.07 �.01 �.08 �.23Gender (1 � male; 2 � female) �.13c �.09 �.02 �.02 �.01 �.01Number of years as Oregon resident (Q55). �.14a �.08 �.04 �.09 �.09 �.16Number of respondents 284 279 293 290 226 46F 4.95 3.56 3.63 2.96 3.33 1.61p .0001 .0001 .0001 .0005 .0002 .1375R-square .1923 .1485 .1445 .123 .1580 .1394

(adjustedR2)

Note. Cell entries are beta coefficients. Coding Q23 � 26: 1 � ‘‘Strongly oppose,’’ 4 � ‘‘Strongly support.’’ Coding Q18 � 22: 1 �

‘‘Strongly disagree,’’ 4 � ‘‘Strongly agree.’’QUAKERSK � mean of Q10, Q16, and Q17 (high score � high risk/likelihood of earthquake). RISKIDX � mean of Q1 � Q9 andQ11 � 15 (high score � high risk). Coding Q47 � Q48: 1 � ‘‘Definitely against,’’ 6 � ‘‘Definitely for.’’ Q18 � Q26 and Q47 � Q48have been recoded as indicated here. Percentages may not total 100 percent due to rounding.a p � .001.b p � .01.c p � .05.

Another analysis examined how people who hada financial interest in commercial real estate (Ques-tion 58) voted on the $19 per year bond measure. Of23 such people (only 7.2 percent of the 319 registeredvoters) 56.5 percent were in favor of the $19 per yearbond issue and 43.5 percent were against it. This

contrasts with the rest of the registered voter samplewhere 75.2 percent voted for the bond issue and 20.7percent voted against it. In both cases, a majority ofthe two groups supported the bond issue but the levelof support was noticeably less for those who reporteda financial interest in commercial buildings.


Table VII. Percent Votes For and Against the $19/year BondIssue by Age, Residential Ownership, Education, and Reported

Household Income Category (n � 319)

For Against

Agea

18–29 78.5 12.330–54 79.1 19.255� 64.6 30.4

Home ownershipb

Rent 83.2 11.5Own 71.5 25.5

EducationHigh school or less 70.2 26.6Some college/tech school 71.3 22.5College grad� 81.1 15.4

Household incomec

�$30,000 77.7 16.0$30,000–49,999 78.1 18.8$50,000–74,999 83.3 10.4�$75,000 65.4 34.6No answer 63.6 34.6

Note. Cell results exclude ‘‘don’t know’’ and no answer resultsexcept where otherwise noted. Percentages may not total 100 per-cent due to this selection of data and rounding.a p � .05.b p � .01.

6. CONCLUSIONS

The technical aspects of earthquake mitigationare important in saving lives, minimizing propertylosses, and preparing for emergency response underdifficult conditions. Much of the planning and prepa-ration for earthquake events is done by seismologists,engineers, architects, and public officials. Once acredible threat of earthquakes is established for acommunity, these earthquake experts must seekbroader community support for mitigation programsand projects. In the case of Portland, Oregon, thecity’s Bureau of Buildings established a Task Forceof stakeholders to examine the problems and therange of options for public policy. When the TaskForce agreed that additional funding would beneeded to support new earthquake-mitigation effortsby the city, they commissioned a survey to measurepublic support for issuing public bonds. The surveywas constrained in what it could ask of respondentsbut it was designed to test the political climate byasking about the need, range, and priorities of a cityprogram. In this sense, it followed the advice by theEarthquake Engineering Research Institute(16) toknow ‘‘the political climate, both constraints and sup-ports, . . . in which all decision-making processesoccur. This includes recognition of windows of oppor-tunity for choice.’’

The results of the survey showed clear publicrecognition of a significant risk from earthquakes inPortland. This risk perception may reflect three re-cent news events about earthquake risk in the com-munity: the upgrading of risk estimates by seismolo-gists and the grave consideration given to thesefindings on the part of public officials; the widespreaddescriptions of damage from minor earthquakes in1993 at Scotts Mills in northwest Oregon and at Kla-math Falls in southwestern Oregon; the reports ofpast events off the Oregon coast including the firstinstrumented local subduction earthquake, also in1993. Along with the California and Kobe, Japanaccounts, these events appear to reinforce the realityof earthquakes as potentially dangerous and worthyof public policy attention. This prior media attentionto earthquake risks meets the criteria suggested byAlesch and Petak(8) that policy advocates should beready to move forward ‘‘when interest is high andwhen an opportunity to get on the agenda eitherarises or can be generated.’’ Alesch and Petak sug-gested that such opportunities are ‘‘typically openedby strong earthquakes in populated areas.’’ In thecase of Portland, however, the reports of earthquakesin other places through the modern news media alongwith dramatized accounts, the scientific upgrading ofrisk for Portland seems to have raised the awarenessand opened a window of opportunity even thoughan earthquake event was not recorded for the cityitself. In other words, the signals from near and faralerted the Portland respondents to a significantearthquake risk and this provided support for thecity bond proposals. Although the data here are notadequate to test the hypothesis, the survey data mayrecord the effects of a social amplification of risk, asdescribed by Kasperson and his colleagues in theirwork on societal responses to technological haz-ards.(17,18) Modern news communication may amplifyperceptions of risk by providing vivid and dramaticaccounts of major events, earthquakes in this case,and connecting them to local risk estimates by theexperts. This could give the expert risk estimates asignal value and provide a higher level of interest,concern, and willingness to support earthquake miti-gation than would otherwise be the case. Furtherwork is needed to understand the role of the newsmedia and public perceptions of risk from naturalhazards.

Another result of the survey is worth notice—the implied values expressed by the public in re-sponse to the range of possible danger and damagefrom an earthquake event. There was a high priority


placed on protecting vulnerable residents, such aschildren, the elderly, and the sick. This was followedby a very pragmatic value given to protection of pub-lic facilities and services that would be needed foreffective emergency response in case of an earth-quake. Considerable support was expressed for com-munity infrastructure facilities, especially for trans-portation and utilities, which must exist for effectiveemergency response and to facilitate rebuilding thecommunity following an earthquake. These facilitiesare basic to ongoing community and societal interac-tions. There was less emphasis on protecting commer-cial facilities and private properties. These responsesseem to express a clear sense of values for publicactions in response to earthquake risk beginning witha societal responsibility to vulnerable people, fol-lowed by mitigation of the effects for all people, andthen the desire to support an ability to recover and re-build.

An interesting issue arises for those conditionswhere vulnerable populations (e.g., the elderly) arehoused in privately owned buildings. Survey respon-dents indicated strong support for helping these peo-ple but there was much less support for actions thatwould seem to benefit private property owners. Itmay be necessary to create priorities within the cate-gory of privately owned buildings and provide differ-ential estimates of risk in order to obtain the broadsupport needed to protect the most vulnerable citi-zens. In pursuing any such program, the public willneed to believe that the costs are primarily benefitingthose vulnerable populations whose safety has wide-spread support.

ACKNOWLEDGMENTS

We would like to acknowledge the assistance ofthe City of Portland, Bureau of Buildings, in particu-lar Ms. Margaret Mahoney, Director of the Bureauof Buildings, and the members of the Task Force onthe Seismic Strengthening of Existing Buildings inthe conduct of the Portland Earthquake Survey andin the preparation of this report. Ms. Leisha Mullicanat Decision Research prepared the graphics and thefinal manuscript for the report. This paper utilizedinformation from the report and data that were pre-pared under a contract between Decision Researchand the City of Portland, Bureau of Buildings. How-ever, any opinions, findings, conclusions, or recom-mendations are those of the authors and do not neces-

sarily reflect the view of the persons or organizationsnamed here.

REFERENCES

1. R. T. Eguchi, J. D. Goltz, C. E. Tayler, S. E. Chang, P. J.Flores, L. A. Johnson, H. A. Sligson, and N. C. Blais, ‘‘TheNorthridge Earthquake as an Economic Event: Direct CapitolLosses,’’ in The Northridge Earthquake. Analyzing EconomicImpacts and Recovery from Urban Earthquakes: Issues forPolicy Makers (Oakland, CA, Earthquake Engineering Re-search Institute, 1996).

2. T. Beatley and P. Berke, ‘‘Time to Shake up EarthquakePlanning.’’ Issues Sci. Technol. 9, 82–89 (Winter, 1993).

3. W. Dean, ‘‘Seismic Risk and Management in California.’’ InV. Molak, ed, Fundamentals of Risk Analysis and Risk Man-agement (New York, Lewis Publishers, 1997).

4. M. Lindell and R. Perry, ‘‘Hazardous Materials Releases inthe Northridge Earthquake: Implications for Seismic Risk As-sessment.’’ Risk Anal. 17, 147–156 (1997).

5. California Seismic Safety Commission, Status of the Unrein-forced Masonry Building Law, 1995 Annual Report to theLegislature. SSC 95-05 (Sacramento, CA, 1995).

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8. D. Alesch and W. Petak, The Politics and Economics ofEarthquake Hazard Mitigation: Un-Reinforced MasonryBuildings in Southern California. Monograph MG43, NaturalHazards Research Working Paper Series (Boulder, CO,Natural Hazards Research & Applications Information Cen-ter, 1986).

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10. Task Force on Seismic Strengthening of Existing Buildings,Interim Report of the Task Force on Seismic Strengthening ofExisting Buildings (Portland, OR, City of Portland, Bureauof Buildings, March 9, 1995).

11. R. Gregory, P. Slovic, and J. Flynn, ‘‘Risk Perceptions, Stigma,and Health Policy,’’ Health Place 2, 213–220 (1996).

12. P. Slovic and J. Monahan, ‘‘Probability, Danger, and Coercion:A Study of Risk Perception and Decision Making in MentalHealth Law,’’ Law Human Behavior 19, 49–65 (1995).

13. J. Flynn, P. Slovic, and C. K. Mertz, ‘‘Decidedly Different:Expert and Public Views of Risks from a Radioactive WasteRepository,’’ Risk Anal. 13, 643–648 (1993).

14. P. Slovic, ‘‘Are Trivial Risks the Greatest Risks of All? Com-ment on Sjoberg,’’ J. Risk Res. (in press).

15. ‘‘Information Gathering and Interpretation.’’ In P. C. Stern.and H. V. Fineberg, eds, National Research Council, Commit-tee on Risk Characterization, Understanding Risk: InformingDecisions in a Democratic Society, (Washington, DC, NationalAcademy Press, 1996).

16. Earthquake Engineering Research Institute, Public Policy andBuilding Safety (Oakland, CA, Author, 1996).

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public support for earthquake risk mitigation in portland, oregon

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