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Internally Valid Econometric Studies


Edited by ITO Seiro
Published in 2012年3月
Chapter 1
Impacts of an HIV Counselling and Testing Initiative: Results from an Experimental Intervention in South Africa pdf (384KB) / Yutaka Arimoto, Narumi Hori, Seiro Ito, Yuya Kudo, Kazunari Tsukada
We have run experimental interventions in a large firm in South Africa. We combined HIV tests with existing medical check up programs (MSP for manual laborers and HCT for administrative laborers) to increase the uptake. Uptake rate increased dramatically, not only under experimental arms but also under the control arm. By ethnicity, Africans and Colored are the groups that reject tests most often. Indians are consistently showing high uptake rates. Whites and Others have generally high uptake rates but vary by the arms. By route, MSP sample is found to reject the test offers more often. HCT route has higher uptake rates, however, compliance to the check up is lower than MSP sample where the latter is compulsory to take the checks.
We have tried four interventions: delayed notification, opt out, risk assessment, supportive information. Virtually no one exersized the option of delayed notification, so we used it as a control arm. Opt out resulted in robust negative impacts on uptake among Whites-Others in HCT sample. Risk assessment showed marginally significant positive impacts on Whites-Others in MSP sample. Supportive information increased the uptake of Whites-Others by almost 100% at the margin. We thus find substantial heterogeneity in responses. Generally, all experimental arms were ineffective in increasing the uptake of Africans and Colored who are deemed to be difficult to reach out and are inferred to have a
higher chance of infection. This general ineffectiveness is common among both MSP and HCT samples whose educational background differ significantly. We thus conjecture that factors related to their ethnic background to be the possible deterrants to tests.
We find robust and strong negative association of subjective probability of HIV infection with uptake.
Among the takers of HIV tests, we find a positive correlation between infection and subjective probability.
This indicates that there is a group of individuals who correctly expects their true status as HIV positive, yet rejects the tests. This pauses a threat to the containment of the disease. We recommend to ask subjective probabilities and continue targetting the individuals based on reported probabilities.

Chapter 2
Social Relationship and HIV Testing in the Workplace: Evidence from South Africa pdf (147KB) / Yutaka Arimoto, Narumi Hori, Seiro Ito, Yuya Kudo, Kazunari Tsukada
This paper explores how a worker’s relational value with colleagues affects his decision to test for HIV in the workplace. We expect that a
concern of being discovered HIV positive reduces a worker’s incentive to take the test, because he might fail to enjoy the full extent of the value of future relationship with colleagues. Since this expected loss might be reinforced by both the strength and size of social relationship, the negative impact of relational value apparently increases with a worker’s tenure and the number of connected workers. Using a worker’s behavioral data drawn from a large enterprise surveyed in South Africa, this paper provides evidence to support these views. As confidentiality is rigorously enforced in the surveyed enterprise, providing all workers with an excuse to test and/or encouraging them to privately test outside the workplace might be effective when introducing a HIV counseling and testing (HCT) program into the workplace of similar kind. Our findings suggest a great difficulty in designing an effective HCT program into a corporate sector, or more generally, any small community in which members strongly connect to each other.

Chapter 3
An Interim Report on Township Employmemt pdf (809KB) / Yutaka Arimoto, Nobuhiko Fuwa, Seiro Ito, Satoshi Ohira
We have conducted a two year panel survey in four townships in the vicinity of a medium sized industrial city. While the area offers a variety of job opportunities, the unemployment rates, especially among the youth, are strikingly high. Educational achievements among the employed and the unemployed do not differ below high school diploma, suggesting the lack of signaling functions of high school education.
It is also shown that the search methods among the job searchers to be inefficient in terms of time and money which require personal visits to potential employers without dependable prior information. Another popular search method emphasizes the importance of network in finding jobs, which is another manifestation of inefficiency in labor markets.

Chapter 4
Chapter 5
Along with the economic reforms started in the late 1970s, the health system changed considerably in China. The health system deteriorated in the 1980s and the 1990s since the government did not direct much attention to the health sector. The government finally initiated the health system reforms in the late 1990s. The medical insurance system was re-established in both urban and rural areas by the early 2000s, and the insurance coverage has dramatically increased in recent years. However, there remain further challenges in China’s health sector. This study attempts to provide an analysis of remaining challenges in the health sector of China. The empirical analysis using provincial panel-data indicates that scaling up the insurance fund level is necessary to improve the health outcome, i.e., maternity mortality, at the provincial level. In addition, improving the availability of health services is also important to improve local heath in rural China. This study also presents an overview of related studies particularly using micro-data, and summarizes the publicly opened micro-panel data of China for further studies.

Chapter 6
Impact Evaluation of Tertiary Canals pdf (3.55MB) / Seiro Ito, Satoshi Ohira, Kazunari Tsukada
Under the commission from JICA, we conducted a four-round household survey from 2009 to 2010 to estimate the impacts of Kaeng Khoi-Ban Mo (KKBM) Pump Irrigation scheme. Total of 826 households were selected and interviewed. As primary and secondary canals were already in operation at the time of survey, we focused on the impacts of tertiary canals.
It is well known that impact evaluation of infrastructure is difficult. This is due to difficulty in randomization and broad spillover of program impacts that effectively wipes out the control group. Our focus on the tertiary canal was strategically determined in light of these
difficulties: First, tertiary canals are partially constructed and we could expect to employ plot-level difference-in-differences (DID) estimator. Ordering of tertiary canal construction was deternmined administratively, started from the closest area to the pump to the furthest. This ordering is expected to be uncorrelated with farmer ability, and provides credible ground for implementing DID estimator. Second, smaller program impacts due to limited capacity of tertiary canals to serve plots simultaneously allow us to find the control group within the irrigation scheme. The availability of control group in the neighborhood of the treated group lends support for credible impact evaluation. We will examine the impact heterogeneity in the coming rounds of additional surveys.