Hugh Gladwin

Behavioral Model to Understand Household-Level Hurricane Evacuation Decision Making

Hurricanes are one of the most costly natural disasters in the United States and have increased in frequency in the last few years. The critical role of evacuation, particularly for the vulnerable communities, has been realized from some disastrous evacuation experiences in recent hurricanes (for example, Hurricanes Katrina and Rita in 2005). Therefore, a thorough understanding of the determinants of evacuation behavior is needed to protect the loss of lives, especially in the vulnerable communities. However, a household’s decision-making process under a hurricane risk is a very complex process influenced by many factors. This paper presents a model of household hurricane evacuation behavior accounting for households’ heterogeneous behavior in decision making by using original data from Hurricane Ivan. It develops a mixed logit (also known as random-parameters logit) model of hurricane evacuation decision, where random parameters reflect the heterogeneous responses of households caused by a hurricane. We report several factors consistent with some of the previous findings, which are important for understanding household-level evacuation decision making. We also explain the varied influences of some of the determining variables on the hurricane evacuation decision.

An integrated multi-criteria scenario evaluation web tool for participatory land-use planning in urbanized areas: The Ecosystem Portfolio Model

Land-use land-cover change is one of the most important and direct drivers of changes in ecosystem functions and services. Given the complexity of the decision-making, there is a need for Internet-based decision support systems with scenario evaluation capabilities to help planners, resource managers and communities visualize, compare and consider trade-offs among the many values at stake in land use planning. This article presents details on an Ecosystem Portfolio Model (EPM) prototype that integrates ecological, socio-economic information and associated values of relevance to decision-makers and stakeholders. The EPM uses a multi-criteria scenario evaluation framework, Geographic Information Systems (GIS) analysis and spatially-explicit land-use/land-cover change-sensitive models to characterize changes in important land-cover related ecosystem values related to ecosystem services and functions, land parcel prices, and community quality-of-life (QoL) metrics. Parameters in the underlying models can be modified through the interface, allowing users in a facilitated group setting to explore simultaneously issues of scientific uncertainty and divergence in the preferences of stakeholders. One application of the South Florida EPM prototype reported in this article shows the modeled changes (which are significant) in aggregate ecological value, landscape patterns and fragmentation, biodiversity potential and ecological restoration potential for current land uses compared to the 2050 land-use scenario. Ongoing refinements to EPM, and future work especially in regard to modifiable sea level rise scenarios are also discussed.

Changes in Evacuation Decisions Between Hurricanes Ivan and Katrina

Hurricanes cause some of the worst traffic conditions, affecting evacuees’ ability to reach safety before they are subjected to high winds, heavy rain, and flooding. This paper is one of the few to use a panel survey to examine similar household decisions over consecutive hurricanes. The study focuses on Hurricanes Ivan and Katrina, which were of similar strength and followed similar paths, and is fairly comprehensive in the number of traffic-related decisions considered. Contingency tables, binary logit models, and Goodman and Kruskals gamma measure were used to examine the effects of previous decisions on (a) whether to evacuate, (b) day of departure, (c) destination type and location, (d) number of household vehicles taken, and (e) reason for route selection. Through the statistical analyses, it was discovered that (a) to a great extent, citizens made the same decision to evacuate or stay for Katrina as they did for Ivan, and higher incomes were not significant in changing that decision; (b) some evacuees departed earlier, but most evacuees departed on the last day possible; (c) most evacuees selected the same type of accommodations and made the same inside-the-county-or-parish or out-of-the-county-or-parish decisions in consecutive evacuations; (d) the number of household vehicles used in the evacuation did not decrease; and (e) route guidance as a selection criterion did not depend on previous evacuation experience.

How to evacuate: model for understanding the routing strategies during hurricane evacuation

This paper explains a modeling approach that offers better understanding of the routing strategies taken by evacuees to reach a safe destination during hurricane evacuation. Route choice during evacuation is a complex process because evacuees may prefer to take the usual or familiar route on the way to the destination, or they might follow the routes recommended by the emergency officials. Depending on the condition of the traffic stream, sometimes they might switch to a different route to obtain better travel time from the one initially attempted, i.e., the routing behavior is random. By using data from Hurricane Ivan, a mixed (random parameters) logit model is estimated which captures the decision making process on what type of route to select while accounting for the existence of unobserved heterogeneity across households. Estimation findings indicate that the choices of evacuation routing strategy involve a complex interaction of variables related to household location, evacuation characteristics, and socioeconomic characteristics. The findings of this study are useful to determine the manner in which different factions of people select a type of route for a given sociodemographic profile during an evacuation. Language: en

Identifying HIV Risk-Reduction Strategies for Hispanic Populations in Broward County

PURPOSE To improve the effectiveness of behavioral interventions for Hispanic young adults, we studied their perceived risks for HIV infection, lifetime and more recent sexual experiences, use of condoms, and HIV-antibody testing histories. METHODS Logistic regression was used to analyze computer-assisted telephone-interview surveys of 1,596 randomly selected Hispanic residents of 12 high AIDS-incidence ZIP-code areas. RESULTS After we controlled for gender, age, marital status, educational attainment, and language of preference, differences were found by country of origin. Those coming from Peru (adjusted odds ratio [AOR]=3.45; 95%CI=1.85-6.43) and Colombia (AOR=1.94; 95%CI=1.12-3.36) were more likely than U.S.-native Hispanics to perceive their risk of acquiring HIV as above average. Sexually active Mexicans (AOR=1.80; 95%CI=1.04-3.10) were significantly more likely than U.S. natives to have used a condom in the past 12 months. Young adults coming from Puerto Rico (AOR=0.55; 95%CI=0.33-0.91) were less likely than U.S.-native Hispanics to have ever been tested for HIV. Virginity and sexual abstinence were unrelated to country of origin, but respondents interviewed in Spanish were more likely than those interviewed in English to be sexually active (AOR=2.57; 95%=1.39-4.75). CONCLUSIONS To maximize the impact of behavioral interventions, risk-reduction programs must adjust for social and cultural differences within the Hispanic-American population.

ETHNIC DIFFERENCES IN HIV RISk PERCEPTIONS AND BEHAVIORS AMONG BLACk 18-39 YEAR-OLD RESIDENTS OF BROWARD COUNTY, FLORIDA

The study assessed ethnic differences in the perceived risks of HIV infection, sexual experiences, and HIV-antibody testing histories among Black populations in Broward County, Florida. Data were analyzed for 2,731 well-characterized survey respondents 18-39 years old who indicated they were African Americans, Caribbean Islanders, English-speaking, or Creole-speaking Haitians. Creole-speaking Haitians were least likely to consider themselves at risk of HIV infection, report using condoms in the last 12 months, and indicate that they had ever been tested for HIV. English-speaking Haitians were more likely than African Americans to report never engaging in sexual intercourse and were less likely to have ever been tested for HIV. English-speaking Caribbean Islanders reported preventive behaviors similar to those of African Americans, but had lower perceptions of HIV risk and were less likely to have ever been tested. Health promotion programs designed to improve HIV prevention practices must appreciate social and cultural differences among Black populations.

The Role of Social Networks and Information Sources on Hurricane Evacuation Decision Making

AbstractHurricanes often threaten to have catastrophic impacts on the lives of residents in coastal areas of the U.S. Timely evacuation limits this impact, but people may choose to evacuate or not ...

Racial residential segregation and risky sexual behavior among non-Hispanic blacks, 2006–2010

Sexually transmitted infections (STIs) including human immunodeficiency virus (HIV) have disproportionately affected the non-Hispanic black population in the United States. A persons community can affect his or her STI risk by the communitys underlying prevalence of STIs, sexual networks, and social influences on individual behaviors. Racial residential segregation-the separation of racial groups in a residential context across physical environments-is a community factor that has been associated with negative health outcomes. The objective of this study was to examine if non-Hispanic blacks living in highly segregated areas were more likely to have risky sexual behavior. Demographic and sexual risk behavior data from non-Hispanic blacks aged 15-44 years participating in the National Survey of Family Growth were linked to Core-Based Statistical Area segregation data from the U.S. Census Bureau. Five dimensions measured racial residential segregation, each covering a different concept of spatial variation. Multilevel logistic regressions were performed to test the effect of each dimension on sexual risk behavior controlling for demographics and community poverty. Of the 3643 participants, 588 (14.5%) reported risky sexual behavior as defined as two or more partners in the last 12 months and no consistent condom use. Multilevel analysis results show that racial residential segregation was associated with risky sexual behavior with the association being stronger for the centralization [aOR (95% CI)][2.07 (2.05-2.08)] and concentration [2.05 (2.03-2.07)] dimensions. This suggests risky sexual behavior is more strongly associated with neighborhoods with high concentrations of non-Hispanic blacks and an accumulation of non-Hispanic blacks in an urban core. Findings suggest racial residential segregation is associated with risky sexual behavior in non-Hispanic blacks 15-44 years of age with magnitudes varying by dimension. Incorporating additional contextual factors may lead to the development of interventions that promote healthier behaviors and lower rates of HIV and other STIs.

Hurricane Evacuation Route Choice of Major Bridges in Miami Beach, Florida

Evacuation is a typical recourse to prevent loss of life if a high storm surge occurs, especially in hurricane-prone regions. Bridges are the key locations of bottlenecks. Because of the specific geographic shape and roadway network of Miami Beach, Florida, residents need to evacuate over one of the six major bridges or causeways: MacArthur Causeway, Venetian Causeway, Julia Tuttle Causeway, John F. Kennedy Causeway, Broad Causeway, and Haulover Bridge. A mixed logit model is presented to identify the determining factors for evacuees from Miami Beach in selecting one of these bridges during a major hurricane. The model was developed by using data obtained from a survey that included a hypothetical Category 4 (major) hurricane scenario to reveal the most likely plans for evacuees from this area. The estimation findings suggest that the preference over a given bridge involves a complex interaction of variables, such as distance to reach the evacuation destination, evacuation-specific characteristics (evacuation day, time, mode, and destination), and evacuee-specific characteristics (gender, race, evacuation experience, and living experience). The normally distributed random parameters in the model account for the existence of unobserved heterogeneity across different observations. The findings of this study will help emergency officials and policy makers to develop efficient operational measures and better evacuation plans for a major hurricane by determining different fractions of people taking each of the six bridges.

American parents’ willingness to prescribe psychoactive drugs to children: a test of cultural mediators

PurposeIn the USA, white children receive psychoactive drugs more often than black or Hispanic children. This study investigates whether cultural attitudes statistically mediate differences between American parents’ self-identified racial–ethnic group membership and their willingness to medicate children for behavioral problems.MethodsUsing data from telephone interviews with 1,145 parents in two Florida counties, structural models tested associations between each group compared with the other, in willingness to medicate children exhibiting different problematic behaviors and hypothesized cultural (familism, fatalism, attitude toward corporal punishment, religiosity, concern about treatment stigma, birth abroad, language of interview) and other mediators (views about medications and causes of children’s problems). Respondent gender, age, socioeconomic status, parent-type household, taking psychoactive medication, and having a child with behavioral problems were used as covariates.ResultsRace–ethnicity was strongly associated with specific cultural attitudes and views about medications and problems, but only Hispanics distinguished themselves significantly from whites in willingness to medicate children. Across groups, parents who viewed medication favorably and endorsed biomedical causes for problems were more willing to medicate. In Hispanic–white and Hispanic–black comparisons, being interviewed in Spanish was the sole but modest cultural mediator of willingness, and in black–white comparisons, only concern about treatment stigma weakly mediated differences in willingness.ConclusionsThese findings provide faint support for a parent-centered cultural explanation of reported prescription differences among youths of different racial–ethnic groups in the USA. However, structural and professional components of a broader cultural hypothesis for such differences, within the USA and between different countries, still require evaluation.