Publication Type: Conference Paper/Unpublished Manuscript
Abstract: Patterns are not only ubiquitous in nature and quilts, but also in mathematics. The ability to generalize patterns and convert them into algorithms is one aspect of numerical courses that is a foundational tool for mathematicians. This talk will present examples across the numerical curriculum through which students can gain experience in generalizing patterns to develop algorithms.

Publication Type: Paper/Poster Proposal
Abstract: Presence of others in the survey has an effect on the response errors due to the limitation of privacy or confidentiality. Although much has been known about the presence of others in the West, little is known the effect of presence of others in the East. We examined the presence of others in Korean General Social Survey (2003) and General Social Survey (2002). Because Korean General Social Survey adopted General Social Survey in US, both surveys include same questions. Our preliminary analysis shows that only 45% of respondents were interviewed alone in Korea, but 70.1% of respondents in US. This difference appears to relate to the household structure reflecting sociocultural differences. Although people whose culture emphasizes collectivism or interdependence are more likely to be influenced by the presence of others, the effects of presence of others on attitudes about gender roles, marriage, and trusting others were very similar in both countries.

Publication Type: Abstract
Abstract: Rationale: Health care expenditure regressions are used in a wide variety of economic analyses including risk adjustment and program and treatment evaluations. Two recent articles have demonstrated that generalized gamma models with heteroskedasticity (GGM-het) and extended general linear models (EGLM) provide flexible approaches to deal with a variety of data problems commonly encountered in expenditure estimation. To date, however, there have been few empirical applications of these models to expenditures.

Objective: We use nationally representative data from the first six panels of the U.S. Medical Expenditure Panel Survey (MEPS) to compare the bias and predictive accuracy of GGM-het and EGLM models with other regression models in a cross-validation study design.

Methodology: We estimate models of prescription drug, ambulatory and total health care expenditures conditional on having any expenditure. Models are estimated separately for the elderly and other privately insured adults. Since expenditure distributions vary by type of service and population, the appropriate functional form is also likely to vary. In estimating expenditures, we focus on two recently developed modeling approaches that flexibly accommodate skewness, kurtosis, heteroskedasticity and other data problems. The GGM-het model, proposed by Manning, Basu, and Mullahy (2005), uses a log-link like many standard GLM models. However, the GGM-het model is more flexible than standard models because the generalized gamma distribution has a scale parameter and two shape parameters and variance is explicitly modeled as a function of explanatory variables. In the EGLM model, proposed by Basu and Rathouz (2005), the link function is not specified prior to estimation. Instead, both the link and variance functions are simultaneously estimated along with the coefficients.

Our models use socioeconomic characteristics and condition information from the first year of each MEPS panel to predict expenditures in the second year. We use a split-sample cross validation design to compare results from GGM-het, EGLM, log OLS with heteroskedasticity (log-het), linear OLS, Poisson and Gamma models. We use the validation sample to test for over-fitting and to examine predictive ratios and mean prediction errors in the entire sample, in the tails of the distribution and for persons with chronic conditions.

Results: In our preliminary analysis we focused on total expenditures and estimated all types of models except EGLM. We found that the expenditure distribution for the elderly was more kurtotic than the distribution for other adults and the distributions varied in the extent of heteroskedasticity beyond simple functions of the mean. Overall, the GGM-het and log-het models fit the data for privately insured adults very well. However, none of our models was clearly superior for the elderly.

Conclusions: Our preliminary analysis confirms that GGM-het models are robust to a wide variety of common data problems. For some distributions, however, an even more flexible estimator, such as the EGLM model, may be required.

Publication Type: Conference Paper/Unpublished Manuscript
Abstract: This paper uses the new approach of multilevel simultaneous equation model (Steele, Vignoles, and Jenkins 2007). Social trust has been measured at the aggregate level in order for social capital analysts to take the direction of causality into account, while the aggregate measure is vulnerable to the danger of aggregation bias, misestimated standard errors, and heterogeneity of regression among countries. _x000d_Using the World Values Survey’s indicator of generalized trust and Deininger and Squire’s Gini coefficient, the new model confirms that there is significant negative effect of trust on inequality, while it controls both the society-level variable and the individual-level variables: the former includes the effects of corruption (TI Corruption Perceptions Index), Former Communist nations, Protestant share of population, Muslim share of population (CIA), and ethnic diversity (Alesina et al.(2003)); the latter includes voluntary participation in civic associations and trust in institutions. Instrument variable for inequality is the amount of social spending per GDP (IMF Government Finance Statistics), which will affect income inequality but will not directly impact on trust.

Publication Type: Conference Paper/Unpublished Manuscript
Abstract: This paper builds on the institutional self-inventories completed in 2007 assessing the current state of civil-military education at the War College level. The researchers will propose a framework of civil-military competencies for senior officers to fill the current gaps in war college curricula. Approaches to elevating civil-military relations across the curriculum will also be proposed. Finally, making up for deficiencies in civil-military instruction at the lower levels within the military education system will also be explored.