THE GREAT OVERESTIMATION: TAX DATA AND INEQUALITY MEASUREMENTS IN THE UNITED STATES, 1913–1943

Historical measures of income inequality in the United States must grapple with the challenge of data quality. We examine one such problem affecting the well-known estimates of income inequality produced by Piketty and Saez (2003) using the records of the Internal Revenue Service (IRS). Prior to 1943, incomes were self-reported. Combined with lax enforcement on the part of the IRS, self-reporting of incomes could provide a misleading portrait of the income distribution. To test the accuracy of IRS records, we compare them to independently tabulated state income tax returns between 1919 and 1945 from states with more comprehensive and rigorously enforced tax collection procedures. State income tax records show lower overall levels of income inequality than IRS records. However, we still find that top income concentrations declined across the period between 1929 and World War II. These findings attest to the sensitivity of distributional estimation to the reporting selectivity and economic quality of underlying tax data, suggesting that the existing IRS-derived series systematically overstates top-income concentration in the interwar period. (JEL H2, N32, D31, E01)     

Minimizing the number of tardy jobs in two-machine settings with common due date

We consider two-machine scheduling problems with job selection. We analyze first the two-machine open shop problem and provide a best possible linear time algorithm. Then, a best possible linear time algorithm is derived for the job selection problem on two unrelated parallel machines. We also show that an exact approach can be derived for both problems with complexity \(O(p(n) \times \sqrt{2}^n)\), p being a polynomial function of n.     

Vitamin B1 blocks damage caused by hyperglycemia

Diabetes accelerates the aging process and leads to complications that include blindness, renal failure, nerve damage, stroke, and cardiovascular disease. It has been hypothesized that high plasma glucose concentrations are responsible for increased mitochondrial free radical production and subsequent inactivation of glyceraldehyde phosphate dehydrogenase (GAPDH) in vascular endothelial cells and other cells implicated in these complications. As a result of the decreased ability of GAPDH to process upstream metabolites, three pathways of metabolic damage are activated, which include the advanced glycation end-product formation pathway, the protein kinase C pathway, and the hexosamine pathway. All three pathways have been implicated in abnormal cell signaling in diabetes. A group of German and U.S. scientists has now found that treating diabetic rats with high doses of benfotiamine, a lipid-soluble form of vitamin B1, can prevent diabetic retinopathy and all three forms of metabolic damage by stimulating transketolase activity and thus diverting excess metabolites toward the pentose pathway. Although vitamin B1 is available over the counter, the researchers at this time do not advocate self-treatment without further clinical data.     

The mediating role of work-to-family conflict in the relationship between shiftwork and depression

Abstract

With significant segments of the working population involved in shiftwork, there is the possibility of serious health outcomes. There are two possible pathways to ill health. In the biological pathway the body's circadian rhythms are affected, leading to physiological disturbances and the inability to cope. By contrast, the aim of this study is to elucidate a social pathway by which shiftwork may lead to mental ill health. It examines the mediating influence of work-to-family conflict in the association between shiftwork and depression. Gender differences are also investigated. The sample included 2,931 Canadian respondents with a spouse and at least one child living at home. Close to 28% of respondents were involved in some form of shiftwork. Structural equation modelling supported partial mediation through work-to-family conflict. Further analyses found that mediation was supported in sub-samples of male and female respondents. The results, however, suggest that the experience of shiftwork is quite similar for men and women as no significant differences were found between mediating models. Overall, the findings support the social explanation of the effect of shiftwork on mental health, but they do not rule out other social or biological pathways.     

Transaction‐Specific Investments,Relational Norms,and ERP Customer Satisfaction: A Mediation Analysis*

Integrating the perspectives of transaction cost economics, the resource‐based view, and resource dependency theory, this study analyzes the institutional settings of enterprise resource planning (ERP) implementations in China. Specifically, it examines how bilateral transaction‐specific investments (TSIs) and relational governance mechanisms influence customer satisfaction with ERP implementations. The model is empirically tested using data from on‐site interviews with 208 ERP customers in China. The results demonstrate that the effects of vendors’ and customers’ TSIs on customer satisfaction are facilitated by multiple‐stage micromediational chains. The influence of TSIs on customer satisfaction is mediated by relational norms, and the impact of relational norms on customer satisfaction is bridged by perceived service quality and customer trust. Furthermore, the influence of vendors’ TSIs is stronger than the influence of customers’ TSIs. The findings contribute to business research and practice by providing valuable insights into how ERP vendors and customers should strategize TSIs to enhance relationship performance.     

Assessing the Performance of a Classification‐Based Vulnerability Analysis Model

In this article, a classification model based on the majority rule sorting (MR‐Sort) method is employed to evaluate the vulnerability of safety‐critical systems with respect to malevolent intentional acts. The model is built on the basis of a (limited‐size) set of data representing (a priori known) vulnerability classification examples. The empirical construction of the classification model introduces a source of uncertainty into the vulnerability analysis process: a quantitative assessment of the performance of the classification model (in terms of accuracy and confidence in the assignments) is thus in order. Three different app oaches are here considered to this aim: (i) a model–retrieval‐based approach, (ii) the bootstrap method, and (iii) the leave‐one‐out cross‐validation technique. The analyses are presented with reference to an exemplificative case study involving the vulnerability assessment of nuclear power plants.     

An individual-based model for competingDrosophila populations

An individual-based model forDrosophila is formulated, based on competition amongst larvae consuming the same batch of food. The predictions of the model are supported by data for single speciesDrosophila populations reared in the laboratory. The model is used to build a simple discrete model for the dynamics ofDrosophila populations that are kept over a number of generations. The dynamics of a single species is shown to give either a stable equilibrium or fluctuations which can be periodic or chaotic. When the dynamics of a species in the absence of the other is periodic or chaotic, we found coexistence or two alternative states, on neither of which the species can coexist.     

Long range planning of paper and board supplies

Most standard textbooks identify three essential elements of effective corporate planning: an information input of appropriate depth, critical appraisal of the company's relative position and application of advanced evaluation techniques. Extension of the vision period, for long range or strategic planning, will unavoidably introduce further complexities into these constituent routines of corporate planning as well as into the strategic decision making process. The author reviews the long term outlook for paper and board suppliers and users and points out the strategic advantages of these basic materials.