Assessing Student Ability to Interpret Regression Diagnostic Plots

Simple linear regression analysis is an important component of introductory statistics courses, and testing the validity of its assumptions is an important part of regression modeling and analysis. The traditional approach in introductory statistics courses is to use residual plots to assess possible departures from the key assumptions. Confirmatory statistics are typically not used. But do undergraduate students in these introductory courses have the ability to assess residual plots correctly? This paper presents the results of an Institutional Review Board (IRB) approved study to address this question. The results are interesting and have implications for the teaching of regression in introductory courses as well as for textbook authors who cater to these courses.

A Case for using a Real Asset Transaction Approach for Estimating the Cost of Capital from Rural Telephone Company Data

This paper develops a real asset transaction approach for estimating the cost of capital for rural telephone companies whose financial assets are not publicly traded. The transaction approach uses the actual purchase prices of rural local exchange carriers (RLECs)’ properties and cash flows for estimating the rate of return required by buyers and sellers of RLEC properties. The transaction approach produces higher cost of capital estimates than a traditional approach using a weighted average of debt and equity costs of proxy companies traded on organized exchanges. The estimated difference is in line with the risk premium estimated for small non-traded companies estimated by Duff and Phelps Ibbotson.

Minimum Instructional Hours at School and Childhood Weight

Increasing weight of children in the United States (U.S) has been a persistent public health issue for decades. According to the Center for Disease Control, in the 1963–1970 period, 4% of children between the ages of 6 and 11 were defined to be overweight; that level had more than tripled by 1999, reaching 13% and is even higher today. Childhood obesity is especially common among minority schoolchildren, with approximately 20% of whom are now overweight. Obesity in the U.S. currently cost close to $200 billion a year and accounts for over 20% of all healthcare cost. In seeking explanations for the increase in childhood weight, it is unclear whether childhood obesity arises primarily from school or non-school influences and how school instructional hours can impact a child’s overall health. Therefore, it is important to determine how instructional time at schools and educational institutions potentially impacts a children’s physical health. In this study, we use state-level variations in the minimum amount of instructional time to study the effect of the amount of time spent at school on children’s physical health. We find that an increase in the number of school hours reduces childhood obesity in African Americans by close to .13 percentage points.

Organizational Culture and Impact on Opportunities for Professional Advancement

This paper explores why some demographics, who are relatively new to the ranks of white collar corporate America, may encounter difficulties while navigating the unwritten rules that create the foundation for success in contemporary corporate culture; and suffer unintended consequences to their employment and career advancement. Here we discuss evolving paradigms of diversity initiatives including diversity as demographics vs. diversity of ideas, and how organizational culture may impact the attainment of diversity goals, and by extension, attainment of promotional opportunities for corporate novices. Finally, this paper will examine the role of business organizations in valuing diversity, and the obligation of educational institutions in preparing diverse candidates with knowledge of business etiquette and valuing business culture.

Ethics–Comparing Ethical Egoism with Confucius’s Golden Rule

Both the Eastern and Western societies have an extensive and celebrated history of ethics education. Although normative ethics have been rigorously studied epistemologically and vigorously debated, abstract ethics theories are very difficult to interpret or apply. On the other hand, applied ethical standards can usually provide more direct guidance on specific personal or business conduct in determining whether it is ethical. In this paper, we will focus on the Ethical Egoism principle. Five examples of real-world personal and/or business conducts will be provided to demonstrate how to apply this ethical standard. We will also apply Confucius’s Golden Rule to the same examples in determining whether the similar ethical evaluations can be observed.