Publication Type: Research Report
Abstract: In this paper we present different approaches and outcomes of two grade 4 students who were participants in an intervention study for the development of an understanding of functions through patterns. We contrast one student who used multiple representations (visual, narrative and numeric) to another who relied exclusively on numeric tables to reveal the affordances and limitations of these approaches.

Publication Type: Conference Paper/Unpublished Manuscript
Abstract: Although social networking sites are among the most popular and most discussed internet destinations, research has yet to provide a strong descriptive base for understanding the characteristics of members and their activities. This limits our ability to evaluate claims regarding the extent to which social networking sites function as venues for social relationships and community. Personal profiles on MySpace were examined in order to provide a descriptive frame for evaluating the world’s largest social networking site. Profiles (N = 2000) were randomly selected and coded for communicative affordances associated with membership characteristics and functions, personal expression, and social connection. Results suggested that MySpace was a far less social place that is frequently presumed. Approximately 20% of the profiles had been abandoned or deleted, while another 5% represented entertainers, celebrities, political figures, or commercial interests. Over half of the owners of the remaining profiles had not logged in within the previous 2.5 months and almost 20% had not logged in for over a year. Most (72%) allowed public views of their profiles, but only 22% customized their profiles and less than half (41%) displayed a personal picture. MySpace’s counts of friends were found to be inflated. When corrected, approximately 55% of those with public profiles listed no friends and another 10% listed only one or two. Nearly 62% had received no comments from friends. The overall pattern of low social involvement was observed across all demographic groups. These results challenge the common metaphor of social networking sites as “communities.”

Publication Type: Abstract
Abstract: The predominance of homeownership in many rural areas has overshadowed the importance of the rental housing stock and the needs of rural renters. Rural rental households experience some of the most significant housing problems in the United States. Additionally, a significant portion of federally subsidized rental properties are at risk of being lost as low-income housing due to “prepayment” and “opt-out” clauses. This study analyzes the location, composition, and proximity of federally subsidized rental housing properties and units in rural communities. Various contextual factors integral to rental housing preservation, such as population decline, rurality, and urbanization, minority populations and local housing characteristics, are incorporated into the analysis.

Publication Type: Abstract
Abstract: Rationale: Much has been told about how technological advancements have lowered the price of food and reduced physical demands of work, both of which have been attributed to increased body mass amongst Americans. However, while this explanation of obesity does explain long-term trends in body mass, it should not be forgotten that basically obesity is a micro-level phenomenon. At any point in time individuals take technological advancements as given and then they make behavioral choices which show up in heterogeneity in the weight outcomes. These individual choices are a function of various socio-economic processes which may interact in various ways.

Objectives: The objective of this paper is to analyse the determinants of physical exercise and its impact on body mass.

Methodology: We estimate a system of simultaneous equations where weight is determined by exercise levels besides various socio-economic factors and exercise level is in turn determined by weight and various socio-economic factors. We believe that exercise by its sheer time intensiveness has a large time cost, even when its direct monetary costs may be low, for example in a simple exercise of walking in the park. The time costs therefore add to the opportunity costs of undertaking physical exercise. To the extent that individuals are uniformly endowed with 24 hours in a day, clearly they will allocate their time such as to maximize their utility a crucial component of which is the money or budget constraints. Thus allocation of time to physically demanding activities will determine the body weight of an individual. However, the need to do exercise may itself be motivated by the body weight. We use the NLSY79 data for the years 1998-2002, the only years for which the NLSY explicitly asked questions on physical activity level. To our knowledge there is no other paper which has used this aspect of NLSY till now.

Results: Preliminary analysis suggests that lack of physical exercise can explain part of an increase in body-weight of an individual. Additionally we find that physical exercise, is most lacking in some income groups.

Conclusions: To the extent that individuals do not choose the technology levels in the economy, their choices are revealed through their use of their resources such as to maximize utility. Since overweight does have a disutility clearly individuals who still end up with an uncomfortable level of body weight must be constrained either by money income, or low discount rates, or time. We approached the problem of obesity from time perspective, and our analysis suggests that policy should intervene in the time use of individuals such as to gear them towards some regular basic level of physical exercise.

Publication Type: Abstract
Abstract: Understanding the affordability of coverage is important for evaluating the role of policy in reducing the number of uninsured workers. We study worker health insurance take-up and coverage decisions using data from the Medical Expenditure Panel Survey (MEPS) from 1997 to 2003. Unlike previous studies which control only for current income, we include information on the presence and value of family-level assets such as home ownership, vehicles, savings accounts, stocks, bonds, retirement accounts, as well as liabilities, to estimate the effect of net wealth on insurance purchase decisions. Unlike most studies which focus on “worker” take-up, we also take into account the availability of insurance offers through the spouse’s employer in estimating enrollment decisions of workers and their families.

We estimate worker demand for employer sponsored health insurance as a function of the premium as well as worker, family, employer and plan characteristics. We use two approaches to deal with the lack of premium data for workers who decline coverage. The first approach uses a sub sample in MEPS from 1997-1999 with linked data from the Household Component (HC) and the Insurance Component (IC) which is a survey of employers. Although the HC-IC link sample is not nationally representative, it contains data on the premiums for takers and decliners as well as the availability of choice of health plans, and types of plans offered. The second approach uses simulated premiums from the Insurance Component List Sample. Using the nationally representative sample of employers in the MEPS-IC, we estimate average plan premiums as a function of predictor variables available on both the employer and household surveys, including location (state, MSA), firm size, industry, and plan types offered. We then use this model to predict premiums for workers in the household survey.

Among adults living in families with health insurance offers in 2001 and 2002, 7.6 percent did not take up private insurance. As expected, probability of take up declined with income: 8.6 percent of adults with middle income, 19.9 percent of adults with low income, and 32.4 percent of poor and near poor adults did not take up private insurance. (Bernard and Selden, 2005) Preliminary work based on this sample, suggests that assets and net wealth play a significant role in insurance coverage decisions. Controlling for income, adults who did not take up health insurance were significantly less likely to have assets. For example, among poor and low income adults, the decliners were less likely to own homes (46% vs. 54%), less likely to have cars (78% vs. 86%), less likely to have checking accounts (37% vs. 51%), less likely to have stocks (1% vs. 5%), and less likely to have individual retirement accounts (13% vs. 22%). Research using affordability thresholds based on income has shown that health insurance was affordable to between 25% to 75% of the uninsured in 2000. (Bundorf and Pauly, 2002) Our preliminary results suggest that in explaining health insurance purchase decisions, affordability thresholds based solely on income may be inadequate.