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Open Access Publications from the University of California

Scholarly Works (16 results)

  • Article
Recent Work (2008)

Understanding the possible pitfalls of survey data is critical for empirical research. Among other things, poor data quality can lead to biased regression estimates, potentially resulting in incorrect interpretations that mislead researchers and policymakers alike. Common data problems include difficulties in tracking respondents and high survey attrition, enumerator error and bias, and respondent reporting error. This paper describes and analyzes these issues in Round 1 of the Kenyan Life Panel Survey (KLPS-1), collected in 2003-2005. The KLPS-1 is an innovative longitudinal dataset documenting a wide range of outcomes for Kenyan youths who had originally attended schools participating in a deworming treatment program starting in 1998. The careful design of this survey allows for examination of an array of data quality issues. First, we explore the existence and implications of sample attrition bias. Basic residential, educational, and mortality information was obtained for 88% of target respondents, and personal contact was made with 84%, an exceptionally high follow-up rate for a young adult population in a less developed country. Moreover, rates of sample attrition are nearly identical for respondents who were randomly assigned deworming treatment and for those who were not, a key factor in the validity of subsequent statistical analysis. One vital component of this success is the tracking of respondents both nationally and across international borders (in our case, into Uganda), thus we discuss in detail the costs and benefits of tracking movers. Finally, we study KLPS-1 data quality more broadly by examining enumerator error and bias, as well as survey response consistency. We conclude that the extent of enumerator error is low, with an average of less than one recording error per survey. Errors decrease over time as enumerator experience with the survey instrument increases, but increase over the course of multiple interviews within a single day, presumably due to fatigue. We do find some evidence that the enumerator-respondent match in terms of gender, ethnicity, and religion correlates with responses regarding trust of others and religious activities, suggesting some field officer bias on sensitive questions. Reporting reliability is analyzed using respondent re-surveys. These checks show high levels of consistency across survey/re-survey rounds for the respondent’s own characteristics and personal history,with lower reliability rates on questions asked about others’ characteristics. The steps taken in the design of KLPS-1 to avoid common errors in survey data collection greatly improved the quality of this panel dataset, and provide some valuable lessons for future field data collection projects.

    Cover page: Tracking, Attrition and Data Quality in the Kenyan Life Panel Survey Round 1 (KLPS-1)
    • Article
    CEGA Working Papers (2015)
      Cover page: Worms at work: Long-run impacts of a child health investment
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2016)
        Cover page: Commentary: Assessing long-run deworming impacts on education and economic outcomes: a comment on Jullien, Sinclair and Garner (2016)Creative Commons 'BY' version 4.0 license
        • Article
        CEGA Working Papers (2020)
        Nearly 5.6 million Syrian refugees were displaced by the country’s civil war, of which 50% percent are children. Given the heightened risks of psychological distress for this population it is critical to efficiently and accurately assess well-being for this population for intervention. A digital analysis of features in children’s drawings potentially represents a rapid, cost-effective, and non-invasive method for collecting individual and aggregate data on children’s mental health. Using data collected from free drawings and self-portraits from over 2,500 Syrian refugee children in Jordan across two distinct datasets, we use regression and Lasso machine-learning techniques to understand the relationship between exposure to violence and different measures of psychological trauma. Our results suggest that individual drawing characteristics are strongly correlated with validated measures of psychological trauma and past exposure to violence, with child mental health declining with increased exposure to violence and improving with resettlement in host communities. These results serve as a proof-of-concept for the potential use of children’s drawings as a diagnostic tool in human crisis settings.
          Cover page: Identifying Psychological Trauma among Syrian Refugee Children for Early Intervention: Analyzing Digitized Drawings using Machine Learning
          • Article
          • Peer Reviewed
          UC Berkeley Previously Published Works (2022)
          The impact of urban migration on ethnic politics is the subject of long-standing debate. “First-generation” modernization theories predict that urban migration should reduce ethnic identification and increase trust between groups. “Second-generation” modernization perspectives argue the opposite: Urban migration may amplify ethnic identification and reduce trust. We test these competing expectations with a three-wave panel survey following more than 8,000 Kenyans over a 15-year period, providing novel evidence on the impact of urban migration. Using individual fixed effects regressions, we show that urban migration leads to reductions in ethnic identification; ethnicity's importance to the individual diminishes after migrating. Yet urban migration also reduces trust between ethnic groups, and trust in people generally. Urban migrants become less attached to their ethnicity but more suspicious. The results advance the literature on urbanization and politics and have implications for the potential consequences of ongoing urbanization processes around the world.
            Cover page: Deepening or Diminishing Ethnic Divides? The Impact of Urban Migration in KenyaCreative Commons 'BY' version 4.0 license
            • Article
            • Peer Reviewed
            UC Berkeley Previously Published Works (2021)
            Estimating the impact of child health investments on adult living standards entails multiple methodological challenges, including the lack of experimental variation in health status, an inability to track individuals over time, and accurately measuring living standards and productivity in low-income settings. This study exploits a randomized school health intervention that provided deworming treatment to Kenyan children, and uses longitudinal data to estimate impacts on economic outcomes up to 20 y later. The effective respondent tracking rate was 84%. Individuals who received two to three additional years of childhood deworming experienced a 14% gain in consumption expenditures and 13% increase in hourly earnings. There are also shifts in sectors of residence and employment: treatment group individuals are 9% more likely to live in urban areas, and experience a 9% increase in nonagricultural work hours. Most effects are concentrated among males and older individuals. The observed consumption and earnings benefits, together with deworming's low cost when distributed at scale, imply that a conservative estimate of its annualized social internal rate of return is 37%, a high return by any standard.
              Cover page: Twenty-year economic impacts of dewormingCreative Commons 'BY-NC-ND' version 4.0 license
              • Article
              • Peer Reviewed
              UC Berkeley Previously Published Works (2015)
              We discuss how evidence and theory can be combined to provide insight on the appropriate subsidy level for health products, focusing on the specific case of deworming. Although intestinal worm infections can be treated using safe, low-cost drugs, some have challenged the view that mass school-based deworming should be a policy priority. We review well-identified research which both uses experimental or quasiexperimental methods to demonstrate causal relationships and adequately accounts for epidemiological externalities from deworming treatment, including studies of deworming campaigns in the Southern United States, Kenya, and Uganda. The existing evidence shows consistent positive impacts on school participation in the short run and on academic test scores, employment, and income in the long run, while suggesting that most parents will not pay for deworming treatment that is not fully subsidized. There is also evidence for a fiscal externality through higher future tax revenue, which may exceed the cost of the program. Our analysis suggests that the economic benefits of school-based deworming programs are likely to exceed their costs in places where worm infestations are endemic. This would likely be the case even if the benefits were only a fraction of estimates in the existing literature.
                Cover page: When Should Governments Subsidize Health? The Case of Mass DewormingCreative Commons 'BY' version 4.0 license
                • Article
                • Peer Reviewed
                UC Davis Previously Published Works (2024)
                Green sturgeon (Acipenser medirostris) are an anadromous threatened species of sturgeon found along the Pacific coast of North America. The southern distinct population segment only spawns in the Sacramento River and is exposed to water temperatures kept artificially cold for the conservation and management of winter-run Chinook salmon (Oncorhynchus tshawytscha). Past research has demonstrated costs of cold-water rearing including reduced growth rates, condition and survivorship of juvenile green sturgeon. Our research investigates how the stressors of water temperature and food limitation influence the metabolic performance of green sturgeon. We reared green sturgeon at two acclimation temperatures (13 and 19°C) and two ration amounts (100% and 40% of optimal feed). We then measured the routine and maximum metabolic rates (RMR and MMR, respectively) of sturgeon acclimated to these rearing conditions across a range of acute temperature exposures (11 to 31°C). Among both temperature acclimation treatments (13 or 19°C), we found that feed restriction reduced RMR across a range of acute temperatures. The influence of feed restriction on RMR and MMR interacted with acclimation temperature. Fish reared at 13°C preserved their MMR and aerobic scope (AS) despite feed restriction, while fish fed reduced rations and acclimated to 19°C showed reduced MMR and AS capacity primarily at temperatures below 16°C. The sympatry of threatened green sturgeon with endangered salmonids produces a conservation conflict, such that cold-water releases for the conservation of at-risk salmonids may constrain the metabolic performance of juvenile green sturgeon. Understanding the impacts of environmental conditions (e.g. temperature, dissolved oxygen) on ecological interactions of green sturgeon will be necessary to determine the influence of salmonid-focused management.
                  Cover page: Effects of acclimation temperature and feed restriction on the metabolic performance of green sturgeon.Creative Commons 'BY' version 4.0 license
                  • Article
                  CEGA Working Papers (2020)
                  This study exploits a randomized school health intervention that provided deworming treatment to Kenyan children and utilizes longitudinal data to estimate impacts on economic outcomes up to 20 years later. The effective respondent tracking rate was 84%. Individuals who received 2 to 3 additional years of childhood deworming experience an increase of 14% in consumption expenditure, 13% in hourly earnings, 9% in non-agricultural work hours, and are 9% more likely to live in urban areas. Most effects are concentrated among males and older individuals. Given deworming's low cost, a conservative annualized social internal rate of return estimate is 37%.
                    Cover page: Twenty Year Economic Impacts of Deworming
                    • Article
                    • Peer Reviewed
                    UC Davis Previously Published Works (2025)
                    Sturgeon are threatened by anthropogenic changes to river systems, including entrainment or impingement at water diversions (i.e. the unwanted passage of fish through a water intake or physical contact with a barrier screen, likely caused by high intake velocities). Though there are no universally accepted protocols to determine water diversion risk, previous studies on sturgeon suggest that laboratory evaluations of swimming performance are an effective way to describe susceptibility to entrainment or impingement. The swimming performance of juvenile Green Sturgeon (~5 cm fork length), Acipenser medirostris, was quantified for fish acclimated to 13 and 18°C for 2 weeks using fixed water velocity endurance tests. Water velocities ranged from 25 to 55 cm s-1, and time-to-fatigue was measured at 5 cm s-1 increments. Green Sturgeon were quicker to exhaust at the lower acclimation temperature (13°C) compared to fish acclimated to 18°C, for example at 40 cm s-1 13°C acclimated fish impinged ~7.7 times faster than 18°C acclimated fish and ~41.3 times quicker at water velocities of 45 cm s-1. Whole-body cortisol grouped by time-to-fatigue (i.e. sustained swimming: time-to-fatigue >200 min, prolonged swimming: time-to-fatigue between 5 and 200 min, rapid swimming: time-to-fatigue <5 min, and non-swimming: control fish) was highest following the swimming experiment for fish utilizing prolonged swimming strategies regardless of temperature exposure. Furthermore, whole body lactate was elevated in fish utilizing prolonged and rapid swimming strategies compared to sustained and control non-swimming fish. Taken together, when swimming to exhaustion, these results suggest that Green Sturgeon were upregulating stress markers and relying on anaerobic metabolism, although both the above trends were driven by 18°C acclimated fish. The time-to-fatigue data suggest that the risk of entrainment was reduced to zero at water speeds ≤ 29.4 cm s-1 for 18°C and ≤ 22.6 cm s-1 for 13°C acclimated fish.
                      Cover page: Endurance swimming performance and physiology of juvenile Green Sturgeon (Acipenser medirostris) at different temperatures.
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