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22. Reducing Bias in Treatment Effect Estimation in Observational Studies Suffering from Missing Data
- Author:
- Jennifer Hill
- Publication Date:
- 01-2004
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- Matching based on estimated propensity scores (that is, the estimated conditional probability of being treated) has become an increasingly popular technique for causal inference over the past decade. By balancing observed covariates, propensity score methods reduce the risk of confounding causal processes. Estimation of propensity scores in the complete data case is generally straightforward since it uses standard methods (e.g. logistic regression or discriminant analysis) and relies on diagnostics that are relatively easy to calculate and interpret. Most studies, however, have missing data. This paper illustrates a principled approach to handling missing data when estimating propensity scores makes use of multiple imputation (MI). Placing the problem within the framework of the Rubin Causal Model makes the assumptions explicit by illustrating the interaction between the treatment assignment mechanism and the missing data mechanism. Several approaches for estimating propensity scores with incomplete data using MI are presented. Results demonstrating improved efficacy compared with existing methodology are discussed. These advantages include greater bias reduction and increased facility in model choice.
- Topic:
- Conflict Resolution, Development, Economics, and Education
23. Living at the Edge: America's Low–Income Children and Families
- Author:
- Hsien-Hen Lu, Julian Palmer, Younghwan Song, Mary Clare Lennon, and J. Lawrence Aber
- Publication Date:
- 10-2003
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- By analyzing data from the Current Population Survey March Supplements, Living at the Edge explores the following questions about children in low-income families in the United States: What are the overall changes in the low-income and poverty rates for children over the past quarter century? How has the population of children in low-income families changed over the past decade? Which children are more likel to live in low-income famlies? How have changes in parental employment status affected the likelihood children living in low-income families? What are the state by state variations in child low-income and poverty rates, and how have these changed in the last decade? How does a more inclusive definition of family income and expenses affect our understanding of the poverty and near-poverty rates of children in low-income families?
- Topic:
- Economics, Human Welfare, and Industrial Policy
- Political Geography:
- United States
24. Living at the Edge: America's Low-Income Children and Families
- Author:
- Hsien-Hen Lu, Younghwan Song, Mary Clare Lennon, and J. Lawrence Aber
- Publication Date:
- 10-2003
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- By analyzing data from the Current Population Survey March Supplements, Living at the Edge explores the following questions about children in low-income families in the United States: What are the overall changes in the low-income and poverty rates for children over the past quarter century? How has the population of children in low-income families changed over the past decade? Which children are more likely to live in low-income families? How have changes in parental employment status affected the likelihood of children living in low-income families? What are the state by state variations in child low-income and poverty rates, and how have these changed in the last decade? How does a more inclusive definition of family income and expenses affect our understanding of the poverty and near-poverty rates of children in low-income families? This report helps document significant improvements in the child lowincome rate as well as the significant decrease in the proportion of children who relied on public assistance during the 1990s. However, Living at the Edge also finds a notable increase in the share of children who lived in near-poor families (those with incomes between 100 and 200 percent of the poverty line) among children in low-income families during the 1990s. Many disadvantaged groups of children, including those with young parents, minority parents, parents with limited education, or unmarried parents, were less likely to live in poor or lowincome families in the late 1990s than such children a decade earlier. The improvement in the child low-income rates of these disadvantaged groups was closely related to an increase in parental employment during the late 1990s. However, the low-income rate worsened for children whose more educated parent had a high-school diploma but no college education. For children of many disadvantaged social groups, parental employment appears to do less to protect them from economic hardship then it did a decade earlier. The groups that suffered the most in reduced economic security given parental employment status were those in the medium risk ranks (children in families with at least one parent between ages 25 to 39, children whose more educated parent had only has a high school diploma, and in father-only families). The report also notes that the official measure of poverty ignores the burden of medical and work related expenses as well as taxes and therefore tends to underestimate the share of children in near-poor and low-income families facing economic insecurity. Finally, we discuss the policy implications for our findings.
- Topic:
- Economics, Human Welfare, and Poverty
- Political Geography:
- United States
25. Active Patients' in Rural African Health Care: Implications for Welfare, Policy and Privatization
- Author:
- Kenneth L. Leonard
- Publication Date:
- 03-2003
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- The 'active patient' is introduced in this paper. She is the same person as the rational peasant that we have known for at least three decades. She is a rational agent seeking health care in an environment characterized by market failures (particularly agency in the supply of medical quality) and imperfect institutional responses to these failures. We show evidence that patients significantly increase their welfare by choosing between various different providers and matching their illnesses to the resources that are available at these different providers. This paper suggests that continuing to view patients as passive participants in the health care market gives way to misleading policy suggestions and may in fact reduce the welfare of patients.
- Topic:
- Economics, Human Welfare, and Poverty
- Political Geography:
- Africa
26. Factional Politics and Credit Networks in Revolutionary Vermont
- Author:
- Henning Hillmann
- Publication Date:
- 01-2003
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- Studies of state formation tend to emphasize the demise of localism through centralization. This article specifies empirically the social structural conditions that strengthen localism understate formation. The historical case is the creation of Vermont during the Revolutionary War and the local factionalism it involved. Probate records are used to reconstruct credit networks that provided the relational foundation for localism and factional identities. The evidence demonstrates that network segregation between factional regions intensified over time, and was supported by strong cohesion within these regions. Local brokers who forged cohesion within factions consistently attained important political offices while mediators between opposing factions increasingly failed to obtain offices. This structural process coincided with the shift of Vermont's domestic politics into national level conflicts between Federalists and Jeffersonians. Within this escalation local and national factions crystallized around equivalent pairs of binary categorical oppositions. T h e evocation of national politics directly resonated with local lines of conflict, and reinforced factional identities and localism.
- Topic:
- Government, Human Welfare, Politics, and War
- Political Geography:
- United States
27. The Plasticity of Participation: Evidence from a Participatory Governance Experiment
- Author:
- Subham Chaudhuri and Patrick Heller
- Publication Date:
- 01-2003
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- Under the “People's Campaign for Decentralised Planning,” initiated by the government of the Indian state of Kerala in 1996, significant planning and budgetary functions that had previously been controlled by state-level ministries, were devolved to the lowest tier of government—municipalities in urban areas, and gram panchayats (village councils) in ural areas. A key element of the campaign was the requirement that every gram panchayat organize open village assemblies—called Gram Sabhas—twice a year through which citizens could participate in formulating planning priorities, goals and projects. Using data from the first two years of the campaign, on the levels and composition of participation in the Gram Sabhas in all of Kerala's 990 gram panchayats we empirically assess the explanatory power of the dominant existing paradigms of participation—social capital, rational choice, and social-historical. The basic patterns we document, as well as our more detailed analyses of the impact that a range of spatial, socioeconomic and political factors had on the levels and social depth of participation, provide broad support for a dynamic and contingent view of participation, a perspective that recognizes the “plasticity of participation.”
- Topic:
- Economics, Government, Human Welfare, and Governance
- Political Geography:
- Asia
28. The Role of Effort Advantage in Consumer Response to Loyalty Programs: The Idiosyncratic Fit Heuristic
- Author:
- Ran Kivetz and Itamar Simpson
- Publication Date:
- 12-2002
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- Over the past few years, customer relationship management and loyalty programs (LPs) have been widely adopted by companies and have received a great deal of attention from marketers, consultants, and, to a lesser degree, academics. In this research, we examine the effect of the level of effort required to obtain a LP's reward on consumers' perception of the LP's attractiveness. We propose that, under certain conditions, increasing the program requirements can enhance consumers' likelihood of joining the program, thus leading consumers to prefer a dominated option. Specifically, we hypothesize that consumer s often evaluate LPs based on their individual effort to obtain the reward relative to the relevant reference effort (e.g., the effort of typical other consumers). When consumers believe they have an effort advantage relative to typical others (i.e., an idiosyncratic fit with the LP), higher program requirements manify this perception of advantage and can therefore increase the overall perceived value of the program. This proposition was supported in a series of studies in which the perceived idiosyncratic fit was manipulated either by reducing the individual effort or by raising the reference effort. The findings also indicate that (a) idiosyncratic fit considerations are elicited spontaneously, (b) idiosyncratic fit mediates the effect of effort on consumer response to LPs, and (c) an alternative account for the results based on signaling is not supported. We conclude that these findings are part of a broader phenomenon, which we term the idiosyncratic fit heuristic, whereby a key factor that affects consumers' response to marketing programs and promotional offers is the perceived relative advantage or fit with the individual's idiosyncratic conditions and preferences.
- Topic:
- Development, Economics, Emerging Markets, and Industrial Policy
29. Permanently Beta: Responsive Organization in the Internet Era
- Author:
- Gina Neff and David Strark
- Publication Date:
- 12-2002
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- How has the Internet influenced economic organization? Many approach this question strictly economically by examining the productivity gains from particular technological advances or the roles that dot-coms and other Internet-based organizations play with the economy. We approach this question differently—we move away from a macro-social analysis to consider the co-evolution of new technologies and organizational forms. In other words, how has the process of technological change in the Internet era influenced the way we organize economic activities? In this chapter we discuss how information technologies foster the emergent design and user-driven design of websites and other online media, as well as products and organizations off-line. We also consider how to mitigate the social costs of these changes.
- Topic:
- Economics, Industrial Policy, and Science and Technology
30. Negotiating the End of Transition: A Network Approach to Political Discourse Dynamics, Hungary 1997
- Author:
- Péter Csigó and Balázs Vedres
- Publication Date:
- 12-2002
- Content Type:
- Working Paper
- Institution:
- Institute for Social and Economic Research and Policy at Columbia University
- Abstract:
- The initial question of this paper is how the large scale social process of postsocialist transition ends. We argue that transition is closed by discursive innovations in the political field, rather than just spontaneous crystallization. The political field is depicted as a dynamic symbolic structure that is an arena of local action. First the possible discourse positions are extracted from the two mode network of speech acts and statements. Then using these typical positions the dynamics of responses and responses to responses is explored. We give an account of an emergent univocal government position that represents a successful role claim (an exit from the loops of local action) on the government's side to coherently frame the end of transition.
- Topic:
- Government
- Political Geography:
- Europe