426 research outputs found
Food Security Crop Price Transmission and Formation in Nigeria
The three studies in this dissertation explore the current conditions and operations of markets for seven key food security crops (cassava, cowpeas, maize, millet, rice, sorghum, and yams) in Nigeria.
Chapter 2 is an empirical analysis of the current agricultural statistics system in Nigeria. A number of sources gather and report agricultural statistics for the country. Since there has not been an agricultural census implemented there for multiple decades, however, there is no objective source for data verification. Therefore, this study uses two additional types of “on the ground information” to assess if agricultural production estimates reflect growing conditions: prices and remote sensing data in the form of the normalized difference vegetation index (NDVI). The results show that existing production estimates are poorly correlated with both prices and the NDVI. Prices and the NDVI data are highly correlated, however. These findings imply that existing production estimates do not reflect growing conditions, and, therefore, are of poor quality.
Chapter 3 is a comprehensive analysis of crop price transmission from global and neighbor country prices to Nigerian commercial hub and urban markets, and from commercial hubs to other urban and rural markets within the country. The results show that tradability matters for price transmission, but that tradability varies across crops and scopes of markets. Nigerian urban rice prices are highly correlated with prices on global markets and those in neighboring countries. Coarse grain prices appear disconnected from global markets, however, but move closely with those in neighboring countries. Large margins were estimated for prices of rice imported from global markets (in all regions), and for coarse grains to Southern Nigerian markets only. The existence of large margins implies that there are transactions costs and/or quality premiums that vary systematically with the world price, and/or mark-ups by traders with market power in these markets. While domestic market prices are almost always cointegrated, perfect price transmission is generally found only between commercial hubs and other urban markets. Moreover, long lags were found for price transmission across all scopes of markets, but especially between urban and rural prices in some regions. These results imply that local conditions (e.g., weather) are relatively more important than external market prices for explaining price variation in rural markets, especially in the short-run.
Chapter 4 incorporates NDVI data into price formation models to estimate whether observable growing conditions explain price variation in Nigerian food security crop markets. Four issues related to use of NDVI data that exist within the literature are investigated: whether NDVI is a valid proxy for expected production, how NDVI is a proxy for seasonality, the relationship between market size and the area scope used to average NDVI values across space, and if anomalous harvest expectations can change long-run price variation and price relationships between markets. The results show that information on growing conditions is more informative for isolated than interconnected markets. Even for those local prices, however, other non-weather and non-external market price factors are relatively more important for explanation of price variation.
An implication of these results is that Nigeria cannot plausibly rely solely on direct imports from global markets to meet short-run demand during future weather shock periods. Thus, storage is required to ensure stability of food security, either for imports or domestically produced surpluses acquired in non-crisis periods. Given the isolation of rural markets, local and on-farm stocks are at least as important as large facilities in commercial hubs. Improvement of village level and on-farm storage systems and elimination of other market distortions that inhibit trade between urban and rural markets would make public storage less needed. The findings on poor quality of agricultural statistics indicate a clear priority to improve agricultural data, to facilitate better planning of any food security strategies. A combination of surveys with remote sensed and crowd sourced data may improve feasibility in the funding constrained environment
Do the Poor Pay More for Healthy Food? An Empirical Economic Analysis
Food Consumption/Nutrition/Food Safety,
Legal Remedies to Address Stigma-Based Health Inequalities in the United States: Opportunities and Challenges
Stigma is an established driver of population-level health outcomes. Antidiscrimination laws can generate or alleviate stigma and, thus, are a critical component in the study of improving population health.
Currently, antidiscrimination laws are often underenforced and are sometimes conceptualized by courts and lawmakers in ways that are too narrow to fully reach all forms of stigma and all individuals who are stigmatized.
To remedy these limitations, we propose the creation of a new population-level surveillance system of antidiscrimination law and its enforcement, a central body to enforce antidiscrimination laws, as well as a collaborative research initiative to enhance the study of the linkages between health and antidiscrimination law in the future
Effects of Racial Prejudice on the Health of Communities: A Multilevel Survival Analysis
Objectives. We examined whether and how racial prejudice at both the individual and community levels contributes to mortality risk among majority as well as minority group members.
Methods. We used data on racial attitudes from the General Social Survey (1993–2002) prospectively linked to mortality data from the National Death Index through 2008.
Results. Whites and Blacks living in communities with higher levels of racial prejudice were at an elevated risk of mortality, independent of individual and community sociodemographic characteristics and individually held racist beliefs (odds ratio = 1.24; 95% confidence interval = 1.04, 1.49). Living in a highly prejudiced community had similar harmful effects among both Blacks and Whites. Furthermore, the interaction observed between individual- and community-level racial prejudice indicated that respondents with higher levels of racial prejudice had lower survival rates if they lived in communities with low degrees of racial prejudice. Community-level social capital explained the relationship between community racial prejudice and mortality.
Conclusions. Community-level racial prejudice may disrupt social capital, and reduced social capital is associated with increased mortality risk among both Whites and Blacks. Our results contribute to an emerging body of literature documenting the negative consequences of prejudice for population health
Validity of neonatal jaundice evaluation by primary health-care workers and physicians in Karachi, Pakistan
Objective: The Purpose of this study was to validate primary health-care workers\u27 and physicians\u27 visual assessment of neonatal hyperbilirubinemia in Karachi, Pakistan. Study Design: We compared primary health-care workers\u27 and physicians\u27 clinical identification of jaundice in infants = 15 mg per 100 ml (260 mu mol l(-1)) with 83.3% sensitivity and 50.5% specificity, neonates aged 1 to 6 days were identified with 76.2% sensitivity and 60.7% specificity. Physicians identified neonates aged 1 to 20 days with hyperbilirubimemia \u3e= 15 mg per 100 ml (260 mmol l(-1)) with 51.4% sensitivity and 90.7% specificity, and neonates aged 1 to 6 days with 50% sensitivity and 88.5 % specificity. The primary health-care workers\u27 and physicians\u27 assessments showed fair interobserver agreement (k statistic 0.29). Conclusion: Primary health-care workers identified hyperbilirubinemic neonates with adequate sensitivity. With proper training and supervision, their assessment could improve the referral of hyperbilirubinemic neonates in low-resource settings in the developing world
Spatial market integration of food markets during a shock: Evidence from food markets in Nigeria
This paper uses comprehensive and long time series monthly food price data and a panel dyadic regression framework to evaluate the impact of the COVID-19 pandemic and associated policy responses on spatial market integration across a diverse set of food items in Nigeria. The empirical results reveal several important insights. First, we show that a significant slowdown in the speed of adjustment and price transmission occurred during the pandemic. For some food items, the speed of adjustment and, by implication, spatial market integration weakened by two- to-threefold after the pandemic outbreak. The effect was especially pronounced for perishable food items. Second, lockdown measures and the spread of the pandemic triggered additional dispersion in market prices across markets. For example, lockdown measures were associated with a 5–10 percent reduction in the speed of readjustment toward long-term equilibrium. Third, additional underlying attributes of markets, including lack of access to digital infrastructure and distance between markets, exacerbated impacts associated with the pandemic. For instance, access to Internet service reduced the slowdown in the speed of adjustment caused by the pandemic, but longer distances between market pairs induced greater slowdown in the speed of price transmission. Our findings offer important insights for revitalizing the efficiency of food markets affected by the pandemic. The heterogenous impacts of the pandemic across value chains and markets reinforce the need to properly target post-pandemic recovery interventions and investments. Finally, we offer some insights to reduce the vulnerability of food and market systems to disruptions in future pandemics or similar phenomena that inhibit food marketing and trade
Associations between antibullying policies and bullying in 25 states
Importance Bullying is the most widespread form of peer aggression in schools. In an effort to address school bullying, 49 states have passed antibullying statutes. Despite the ubiquity of these policies, there has been limited empirical examination of their effectiveness in reducing students' risk of being bullied. Objective To evaluate the effectiveness of antibullying legislation in reducing students' risk of being bullied and cyberbullied, using data from 25 states in the United States. Design, Setting, and Participants A cross-sectional observational studywas conducted using a population-based survey of 63 635 adolescents in grades 9 to 12 from 25 states participating in the 2011 Youth Risk Behavior Surveillance System study (September 2010-December 2011). Data on antibullying legislation were obtained from the US Department of Education (DOE), which commissioned a systematic review of state laws in 2011. The report identified 16 key components that were divided into the following 4 broad categories: purpose and definition of the law, district policy development and review, school district policy components (eg, responsibilities for reporting bullying incidents), and additional components (eg, how policies are communicated). Policy variables from 25 states were linked to individual-level data from the Youth Risk Behavior Surveillance System on experiencing bullying and cyberbullying. Analyses were conducted between March 1, 2014, and December 1, 2014. Exposure State antibullying legislation. Main Outcomes and Measures Exposure to bullying and cyberbullying in the past 12 months. Results There was substantial variation in the rates of bullying and cyberbullying across states. After controlling for relevant state-level confounders, students in states with at least 1 DOE legislative component in the antibullying law had a 24%(95%CI, 15%-32%) reduced odds of reporting bullying and 20%(95%CI, 9%-29%) reduced odds of reporting cyberbullying compared with students in states whose laws had no DOE legislative components. Three individual components of antibullying legislation were consistently associated with decreased odds of exposure to both bullying and cyberbullying: statement of scope, description of prohibited behaviors, and requirements for school districts to develop and implement local policies. Conclusions and Relevance Antibullying policiesmay represent effective intervention strategies for reducing students' risk of being bullied and cyberbullied in schools. Copyright 2015 American Medical Association. All rights reserved
Association between an Internet-Based Measure of Area Racism and Black Mortality
Racial disparities in health are well-documented and represent a significant public health concern in the US. Racism-related factors contribute to poorer health and higher mortality rates among Blacks compared to other racial groups. However, methods to measure racism and monitor its associations with health at the population-level have remained elusive. In this study, we investigated the utility of a previously developed Internet search-based proxy of area racism as a predictor of Black mortality rates. Area racism was the proportion of Google searches containing the “N-word” in 196 designated market areas (DMAs). Negative binomial regression models were specified taking into account individual age, sex, year of death, and Census region and adjusted to the 2000 US standard population to examine the association between area racism and Black mortality rates, which were derived from death certificates and mid-year population counts collated by the National Center for Health Statistics (2004–2009). DMAs characterized by a one standard deviation greater level of area racism were associated with an 8.2% increase in the all-cause Black mortality rate, equivalent to over 30,000 deaths annually. The magnitude of this effect was attenuated to 5.7% after adjustment for DMA-level demographic and Black socioeconomic covariates. A model controlling for the White mortality rate was used to further adjust for unmeasured confounders that influence mortality overall in a geographic area, and to examine Black-White disparities in the mortality rate. Area racism remained significantly associated with the all-cause Black mortality rate (mortality rate ratio = 1.036; 95% confidence interval = 1.015, 1.057; p = 0.001). Models further examining cause-specific Black mortality rates revealed significant associations with heart disease, cancer, and stroke. These findings are congruent with studies documenting the deleterious impact of racism on health among Blacks. Our study contributes to evidence that racism shapes patterns in mortality and generates racial disparities in health
Jedi public health: Co-creating an identity-safe culture to promote health equity
© 2016 The Authors. The extent to which socially-assigned and culturally mediated social identity affects health depends on contingencies of social identity that vary across and within populations in day-to-day life. These contingencies are structurally rooted and health damaging inasmuch as they activate physiological stress responses. They also have adverse effects on cognition and emotion, undermining self-confidence and diminishing academic performance. This impact reduces opportunities for social mobility, while ensuring those who "beat the odds" pay a physical price for their positive efforts. Recent applications of social identity theory toward closing racial, ethnic, and gender academic achievement gaps through changing features of educational settings, rather than individual students, have proved fruitful. We sought to integrate this evidence with growing social epidemiological evidence that structurally-rooted biopsychosocial processes have population health effects. We explicate an emergent framework, Jedi Public Health (JPH). JPH focuses on changing features of settings in everyday life, rather than individuals, to promote population health equity, a high priority, yet, elusive national public health objective. We call for an expansion and, in some ways, a re-orienting of efforts to eliminate population health inequity. Policies and interventions to remove and replace discrediting cues in everyday settings hold promise for disrupting the repeated physiological stress process activation that fuels population health inequities with potentially wide application.National Institute on Aging (Grant # R01 AG032632)National Institute on Aging (Grant # T32 AG00221
Sexual orientation and symptoms of common mental disorder or low wellbeing: combined meta-analysis of 12 UK population health surveys
Background Previous studies have indicated increased risk of mental disorder symptoms, suicide and substance misuse in lesbian, gay and bisexual (LGB) adults, compared to heterosexual adults. Our aims were to determine an estimate of the association between sexual orientation identity and poor mental health and wellbeing among adults from 12 population surveys in the UK, and to consider whether effects differed for specific subgroups of the population. Methods Individual data were pooled from the British Cohort Study 2012, Health Survey for England 2011, 2012 and 2013, Scottish Health Survey 2008 to 2013, Longitudinal Study of Young People in England 2009/10 and Understanding Society 2011/12. Individual participant meta-analysis was used to pool estimates from each study, allowing for between-study variation. Results Of 94,818 participants, 1.1 % identified as lesbian/gay, 0.9 % as bisexual, 0.8 % as ‘other’ and 97.2 % as heterosexual. Adjusting for a range of covariates, adults who identified as lesbian/gay had higher prevalence of common mental disorder when compared to heterosexuals, but the association was different in different age groups: apparent for those under 35 (OR = 1.78, 95 % CI 1.40, 2.26), weaker at age 35–54.9 (OR = 1.42, 95 % CI 1.10, 1.84), but strongest at age 55+ (OR = 2.06, 95 % CI 1.29, 3.31). These effects were stronger for bisexual adults, similar for those identifying as ‘other’, and similar for 'low wellbeing'. Conclusions In the UK, LGB adults have higher prevalence of poor mental health and low wellbeing when compared to heterosexuals, particularly younger and older LGB adults. Sexual orientation identity should be measured routinely in all health studies and in administrative data in the UK in order to influence national and local policy development and service delivery. These results reiterate the need for local government, NHS providers and public health policy makers to consider how to address inequalities in mental health among these minority groups
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