83 research outputs found

    Using Target Efficiency to Select Program Participants and Risk-Factor Models: An Application to Child Mental Health Interventions for Preventing Future Crime

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    Statistical risk factor models are often proposed for screening high-risk children to participate in early intervention programs. Recent contributions to the program evaluation literature demonstrate the need for incorporating judgments about relative importance of false positives versus false negatives in screening. This paper formalizes these judgments as commensurable economic costs and benefits and applies them to demonstrate an approach to participant selection motivated by the standard cost-benefit criterion of maximizing expected net benefits. Implications of this approach are explored using data from a mental health prevention trial. We illustrate the response of expected net benefits to the choice of a selection risk level, the sensitivity of the optimal selection risk level to per participant cost/benefit magnitudes, and the use of the target-efficiency approach for choosing among alternative risk-factor models. Several strategies that directly incorporate expected net benefit maximization as a criterion in the model estimation process are also examined.

    Adverse Life Events and Depressive Symptoms in African American Youth: The Role of Control-Related Beliefs

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    The association between experiences of adverse life events and adolescent depressive symptoms has been well documented. However, this association is not consistently observed in urban and low income African American youth. In addition, mechanisms linking life event stress and African American adolescents' depressive symptoms have received little attention. This study examined past year violent and nonviolent life events assessed in 6th grade as predictors of 7th grade depressive symptoms among a community epidemiologically defined sample of 447 (47% girls) urban African American adolescents. Depressive symptoms were assessed twice, at a 1-year interval, and initial depressive symptoms were controlled in the analyses. Control-related beliefs were examined as mediators of the association between life events and depressive symptoms, and gender was examined as a moderator of the association between control-related beliefs and depressive symptoms. Associations among study variables were examined in a series of models, from general to more specific. A model in which nonviolent and violent life events were examined separately and control and contingency beliefs examined as one latent variable was the most informative about the etiology of depressive symptoms in a sample of urban, African American youth. Implications of the findings for preventive interventions and future research are discussed

    Implications of Middle School Behavior Problems for High School Graduation and Employment Outcomes of Young Adults: Estimation of a Recursive Model

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    The potentially serious adverse impacts of behavior problems during adolescence on employment outcomes in adulthood provide a key economic rationale for early intervention programs. However, the extent to which lower educational attainment accounts for the total impact of adolescent behavior problems on later employment remains unclear As an initial step in exploring this issue, we specify and estimate a recursive bivariate probit model that 1) relates middle school behavior problems to high school graduation and 2) models later employment in young adulthood as a function of these behavior problems and of high school graduation. Our model thus allows for both a direct effect of behavior problems on later employment as well as an indirect effect that operates via graduation from high school. Our empirical results, based on analysis of data from the NELS, suggest that the direct effects of externalizing behavior problems on later employment are not significant but that these problems have important indirect effects operating through high school graduation.

    Transitions in Gambling Participation During Late Adolescence and Young Adulthood

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    Purpose: The purpose of this study was to examine transitions in gambling participation from late adolescence into emerging adulthood and to identify factors (i.e., gender, race, intervention status, lunch status, conduct disorder, parental monitoring, neighborhood environment, and substance use) that might influence these transitions. Methods: Markov modeling was used to describe the movement between past-year gambling states (i.e., nongambling and gambling) across 5 years. Annual data on the past-year gambling behavior and substance use were collected from 515 young men and women starting at the age of 17 years. Results: Past-year gambling declined from 51% prevalence at the age of 17 years to 21% prevalence at the age of 22 years. Participants who reported no past-year gambling at a particular annual assessment had more than an 80% probability of also reporting no past-year gambling at the following assessment. Men were 1.07–2.82 times more likely than women to transition from past-year nongambling to gambling year to year, and women were 1.27–5.26 times more likely than men to transition from past-year gambling to nongambling year to year. In addition, gender and past-year tobacco use interacted such that men who used tobacco were most likely (and men who did not use tobacco least likely) to gamble at baseline. Conclusions: Transition rates between gambling states appear to be relatively stable over time from late adolescence into emerging adulthood; however, men and those who engage in substance use may be at an increased risk of gambling participation

    Transitions in Gambling Participation During Late Adolescence and Young Adulthood

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    Purpose: The purpose of this study was to examine transitions in gambling participation from late adolescence into emerging adulthood and to identify factors (i.e., gender, race, intervention status, lunch status, conduct disorder, parental monitoring, neighborhood environment, and substance use) that might influence these transitions. Methods: Markov modeling was used to describe the movement between past-year gambling states (i.e., nongambling and gambling) across 5 years. Annual data on the past-year gambling behavior and substance use were collected from 515 young men and women starting at the age of 17 years. Results: Past-year gambling declined from 51% prevalence at the age of 17 years to 21% prevalence at the age of 22 years. Participants who reported no past-year gambling at a particular annual assessment had more than an 80% probability of also reporting no past-year gambling at the following assessment. Men were 1.07–2.82 times more likely than women to transition from past-year nongambling to gambling year to year, and women were 1.27–5.26 times more likely than men to transition from past-year gambling to nongambling year to year. In addition, gender and past-year tobacco use interacted such that men who used tobacco were most likely (and men who did not use tobacco least likely) to gamble at baseline. Conclusions: Transition rates between gambling states appear to be relatively stable over time from late adolescence into emerging adulthood; however, men and those who engage in substance use may be at an increased risk of gambling participation

    State of the climate in 2018

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    In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and 25billion(U.S.dollars)indamages.InthewesternNorthPacific,SuperTyphoonMangkhutledto160fatalitiesand25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and 6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)
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