scholarly journals Coarsening Bias: How Coarse Treatment Measurement Upwardly Biases Instrumental Variable Estimates

2016 ◽  
Vol 24 (2) ◽  
pp. 157-171 ◽  
Author(s):  
John Marshall

Political scientists increasingly use instrumental variable (IV) methods, and must often choose between operationalizing their endogenous treatment variable as discrete or continuous. For theoretical and data availability reasons, researchers frequently coarsen treatments with multiple intensities (e.g., treating a continuous treatment as binary). I show how such coarsening can substantially upwardly bias IV estimates by subtly violating the exclusion restriction assumption, and demonstrate that the extent of this bias depends upon the first stage and underlying causal response function. However, standard IV methods using a treatment where multiple intensities are affected by the instrument–even when fine-grained measurement at every intensity is not possible–recover a consistent causal estimate without requiring a stronger exclusion restriction assumption. These analytical insights are illustrated in the context of identifying the long-run effect of high school education on voting Conservative in Great Britain. I demonstrate that coarsening years of schooling into an indicator for completing high school upwardly biases the IV estimate by a factor of three.


2019 ◽  
Vol 1 (1) ◽  
pp. 15-21
Author(s):  
Rada Puspita ◽  
Haves Ashan ◽  
Fidiariani Sjaaf

Vision impairment is estimated to affect 285 million people in the world, where 16-20% experience blindness, from the number of blindness suffered at the age of 40-50 years. Cataract seninis is all lens opacities that are found in old age that is above 40 years. The purpose of identifying and collecting frequency data Profile of Senilis cataract patients at the age of 40 years and above at RSI Siti Rahmah Padang in 2017. The research method is descriptive type of research, this study data taken is secondary data, In this study data was taken from the Medical Record at RSI Siti Rahmah Padang. When the study was conducted in February-August 2018, the population of this study were all cataract patients at the age of 40 years and above at RSI Siti Rahmah Padang in 2017 with 80 samples. Data analysis is univariate presented in the form of a frequency distribution table. Results From 80 respondents as many as 40 people (50%) were in the age range of 60-69 years, as many as 42 people (52.5%) patients were male, as many as 31 people (38.8%) patients with high school education and 35 people (43.8%) patients work as private companies. Conclusion In general, most patients are at the age of 60-69 years, the most sex is men, the highest education is high school and most patients are private.



10.31355/12 ◽  
2017 ◽  
Vol 1 ◽  
pp. 063-071
Author(s):  
Agyei Fosu

NOTE: THIS ARTICLE WAS PUBLISHED WITH THE INFORMING SCIENCE INSTITUTE. Aim/Purpose................................................................................................................................................................................................. The main aim of the study is to identify some of the barriers to the integration of technology into the teaching of mathematics in high schools. Background................................................................................................................................................................................................. Writing on chalkboards as a method of transferring knowledge is a key feature of traditional approach to teaching may have been successful in the past, but the minds of the current generation vary from those of the previous generation. Today’s students are immersed in technology. They are much more up-to-date on the latest technology and gadgets. Technology has certainly changed how students access and integrate information, so it plausible that technology has also changed the way students thinks. Growing up with cutting-edge technologies has left them thinking differently than students of past generations. This call for new innovative approaches to teaching that will cater to the students of today. Of course it is not wise to discard the traditional way of teaching that the past teachers have painstakingly created because of its past and some current success. This is why it is recommended to use this approach as a base for the new ones. Thus, if there is a way to transfer the advantages of this approach of teaching to new innovative approach then teachers should do everything in their power to merge the past and the present into one innovative teaching approach. Methodology................................................................................................................................................................................................. Purposeful sampling was used to survey a total of 116 high school mathematics teachers in the former Transkei Homelands. But only 97 questionnaires were deemed usable because of the way they have answered the questions. Microsoft excel was used in the descriptive statistics Contribution................................................................................................................................................................................................. To identify some barriers that need to be addressed by stakeholders, policy makers in high school education so that high school mathematics teachers will be able to integrate technology into their classroom teaching to meet today students’ learning needs. Findings...................................................................................................................................................................................................... The results indicated that the participating teachers need to be trained and supported in the use of the new technologies applicable to teaching mathematics. Recommendations for Practitioners.......................................................................................................................................................... The Eastern Cape department of education needs to consider the lacked of technology training as a barrier to the integration of technology into the teaching of mathematics and take necessary steps to address it. Recommendation for Researchers........................................................................................................................................................... There is the need to explore in depth whether the factors of gender and age also act as barriers. Impact on Society....................................................................................................................................................................................... The research will assist stakeholders, policy makers of high school education to identify the needs of mathematics teachers. That is to say, the skill sets, experience and expertise, as well as teaching equipment and classroom design and environment required by mathematics teachers. Future Research........................................................................................................................................................................................... More work needs to be done to check whether gender, age of the teachers have some effects on their attitude towards technology integration as well as evaluate the role played by choice of teaching methodology and teaching objectives.



2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
J Kalubi ◽  
Z Tchouaga ◽  
A Ghenadenik ◽  
J O'Loughlin ◽  
K L Frohlich

Abstract Background Tobacco use accounts for half the difference in life expectancy across groups of low and high socioeconomic status. The objective was to assess whether social inequalities in smoking in Canada-born young adults are also apparent among same-age immigrants, a group often viewed as disadvantaged and vulnerable to multiple health issues. Methods Data were drawn from the Interdisciplinary Study of Inequalities in Smoking, a longitudinal investigation of social inequalities in smoking in Montreal, Canada. The sample included 2,077 young adults age 18-25 (56.6% female; 18.9% immigrants). Immigrants had been in Canada 11.6 (SD 6.4) years on average. The association between level of education and current smoking was examined separately in immigrants and non-immigrants in multivariate logistic regression analyses controlling for covariates. Results Twenty percent of immigrants were current smokers compared to 24% of non-immigrants. In immigrants, relative to those who were university-educated, the adjusted odds ratio (OR) (95% confidence interval) for current smoking was 1.2 (0.6, 2.3) among those with pre-university or vocational training, and 1.5 (0.7, 2.9) among those with high school education only. In non-immigrants, the adjusted ORs were 1.9 (1.4, 2.5) among those with pre-university or vocational training and 4.0 (2.9, 5.5) among those with high school education. Conclusions Despite a mean of over 10 years in Canada, young adults who immigrated to Canada did not manifest the strong social gradient in smoking apparent in non-immigrants. Identification of factors that protect immigrants from manifesting marked social inequalities in smoking could inform the development of smoking preventive intervention sensitive to social inequalities in smoking. Key messages A social gradient in smoking apparent in Canada-born young adults was not observed in same-age immigrants. Factors that protect immigrants against social inequalities in smoking should be identified.



Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3262
Author(s):  
Mark M. Aloysius ◽  
Hemant Goyal ◽  
Niraj J. Shah ◽  
Kumar Pallav ◽  
Nimy John ◽  
...  

Introduction: We aimed to assess the impact of socio-economic determinants of health (SEDH) on survival disparities within and between the ethnic groups of young-onset (<50 years age) colorectal adenocarcinoma patients. Patients and Methods: Surveillance, epidemiology, and end results (SEER) registry was used to identify colorectal adenocarcinoma patients aged between 25–49 years from 2012 and 2016. Survival analysis was performed using the Kaplan–Meir method. Cox proportional hazards model was used to determine the hazard effect of SEDH. American community survey (ACS) data 2012–2016 were used to analyze the impact of high school education, immigration status, poverty, household income, employment, marital status, and insurance type. Results: A total of 17,145 young-onset colorectal adenocarcinoma patients were studied. Hispanic (H) = 2874, Non-Hispanic American Indian/Alaskan Native (NHAIAN) = 164, Non-Hispanic Asian Pacific Islander (NHAPI) = 1676, Non-Hispanic black (NHB) = 2305, Non-Hispanic white (NHW) = 10,126. Overall cancer-specific survival was, at 5 years, 69 m. NHB (65.58 m) and NHAIAN (65.67 m) experienced worse survival compared with NHW (70.11 m), NHAPI (68.7), and H (68.31). High school education conferred improved cancer-specific survival significantly with NHAPI, NHB, and NHW but not with H and NHAIAN. Poverty lowered and high school education improved cancer-specific survival (CSS) in NHB, NHW, and NHAPI. Unemployment was associated with lowered CSS in H and NAPI. Lower income below the median negatively impacted survival among H, NHAPI NHB, and NHW. Recent immigration within the last 12 months lowered CSS survival in NHW. Commercial health insurance compared with government insurance conferred improved CSS in all groups. Conclusions: Survival disparities were found among all races with young-onset colorectal adenocarcinoma. The pattern of SEDH influencing survival was unique to each race. Overall higher income levels, high school education, private insurance, and marital status appeared to be independent factors conferring favorable survival found on multivariate analysis.





2006 ◽  
Vol 226 (1) ◽  
Author(s):  
Anton L. Flossmann ◽  
Winfried Pohlmeier

SummaryThis paper surveys the empirical evidence on causal effects of education on earnings for Germany and compares alternative studies in the light of their underlying identifying assumptions. We work out the different assumptions taken by various studies, which lead to rather different interpretations of the estimated causal effect. In particular, we are interested in the question to what extend causal return estimates are informative regarding educational policy advice. Despite the substantial methodological differences, we have to conclude that the empirical findings for Germany are quite robust and do not deviate substantially from each other. This also holds for the few studies which rely on ignorability conditions, regardless of whether they use educational attainment as a continuous treatment variable or as a discrete treatment indicator. Own estimates based on the matching approach indicate that the selection into upper secondary schooling is suboptimal



1949 ◽  
Vol 13 (3) ◽  
pp. 359-365
Author(s):  
L. H. Garstin


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