Monte Carlo theoretical trials of methods for assessing statistical significance for differences between adjusted odds ratios

Odds are generally defined as the number of successes divided by the number of failures in a given number of trials. An odds ratio is the ratio of one odds divided by another. Odds ratios can be adjusted to reflect associations with the outcome independently of the influence of associations with other variables. These are adjusted odds ratios. There are several well known methods for comparing odds ratios and testing for statistically significant differences between them. Analogous methods for adjusted odds ratios are not well known or well documented. One method for comparing adjusted odds ratios is explained by Hosmer and Lemeshow (Applied logistic regression, 2000). This method is used for the odds ratios for two variables from the same data set. The purpose of this analysis was to apply this method to a different situation: comparing odds ratios for the same variable from two different data sets. Monte Carlo trials were used to assess the performance of the method and these indicated the method performed well.     

Intergroup contact and reduction of explicit and implicit prejudice toward immigrants: a study with Italian businessmen owning small and medium enterprises

A field study was conducted to test the effectiveness of intergroup contact (Allport, The nature of prejudice, 1954) as a predictor of explicit and implicit attitudes toward immigrants and to examine the processes driving its effects. Participants were Italian businessmen owning small and medium enterprises in Northern Italy who had daily contact with their immigrant workers. We tested a model in which contact ameliorated explicit attitudes, measured as support for social policies toward immigration, through reduced negative outgroup stereotypes. Furthermore, we predicted that contact would have a direct, unmediated effect on improved implicit attitudes toward immigrants, assessed with an Implicit Association Test (Greenwald et al., J Personal Soc Psychol 74:1464–1480, 1998). The results were fully consistent with predictions, thus providing strong support for the contact hypothesis at both an explicit and at an implicit level. The lack of correlation between explicit and implicit attitudes supports dual-process models, suggesting that the two types of attitudes are formed through different processes. The theoretical and practical implications of the findings are discussed.     

Organizational climate for innovation and creative teaching in urban and rural schools

Due to the impact of knowledge-based economies, all countries strive to foster creative education. Research has demonstrated that creativity is influenced both by individual characteristics and by the environment. Previous research examining creative teaching by teachers in Taiwan has typically focused on the relationships between creative teaching and innovative personal characteristics, school leaders’ behaviors, and internal motivation. The purpose of this study was to move beyond prior research to investigate the relationship between creative teaching behaviors and innovation-fostering elements of the organizational climate in schools. In addition, we examined the impact on teacher creativity of urban versus rural school location.     

Time-varying persistence in US inflation

The persistence property of inflation is an important issue not only for economists, but especially for central banks, given that the degree of inflation persistence determines the extent to which central banks can control inflation. Further, not only is it the level of inflation persistence that is important in economic analyses, but also the question of whether the persistence varies over time, for instance, across business cycle phases, is equally pertinent, since assuming constant persistence across states of the economy is sure to lead to misguided policy decisions. Against this backdrop, we extend the literature on long-memory models of inflation persistence for the US economy over the monthly period of 1920:1–2014:5, by developing an autoregressive fractionally integrated moving-average-generalized autoregressive conditional heteroskedastic model with a time-varying memory coefficient which varies across expansions and recessions. In sum, we find that inflation persistence does vary across recessions and expansions, with it being significantly higher in the former than in the latter. As an aside, we also show that persistence of inflation volatility is higher during expansions than in recessions. Understandably, our results have important policy implications.     

Steuerpolitik und Wirtschaftswachstum

The design of the tax system matters for economic growth. During times of economic crisis, tax instruments such as temporary tax cuts can be used to soften adverse effects on the economy by stimulating private and corporate spending. However, empirical evidence suggests that the overall impact of short term tax policies is limited. In the long run, the structure of the tax system is essential to building up an investment friendly and innovation-stimulating environment, which will promote sustainable economic growth.     

What is the potential growth rate of the U.S. economy,and how might policy affect it?

The answer to the question “What will future potential growth be?” is as important as it is unknowable. This paper attempts to predict future U.S. potential output growth by combining what is unknown (future productivity growth, the performance of the labor market) with what is known (the evolution of the age structure of the population). It does so in two ways. First, this paper uses the historical experience of potential labor productivity growth, labor force participation, and weekly hours to simulate a range of outcomes for future potential growth—finding a 90% confidence interval that ranges from 0.7% annual growth to 3.0% annual growth, centered by construction around the Congressional Budget Office projection of 1.8% annual growth. Second, the paper examines a range of specific economic policies that the Trump Administration might pursue in terms of their impact on economic growth both in the short run and over the next decade—finding that an outer bound of these policies could be plus or minus 0.5 percentage point on the annual growth rate, but that these policies would most likely subtract a small amount from growth.     

Visual displays: analytical study and applications to graphs and real data

Principal axis methods such as principal component analysis (PCA) and correspondence analysis (CA) are useful for identifying structures in data through interesting planar graphic displays. However, some kinds of data sets can be dealt alternatively with PCA or CA. This paper focuses on methods, such as PCA and CA, and on visual displays. Our aim is to illustrate the implications for a potential user of selecting either method, and its advantages and disadvantages, from an applied point of view. This is a matter covered broadly in textbooks and elsewhere considering theoretical arguments. Our purpose is to contribute to the comparison between these methods, over the same data set, in order to illustrate them for the practitioner. In the first part of this paper we present a novel analytical study of a binary matrix associated with a non-oriented axis-symmetric graph and show that CA outperforms standardized PCA for the reconstitution and visualization of such kind of graphs. In the second part we present a case using real data dealing with the distribution of employees in different economic sectors for the countries of the European Union, analyzed by means of standardized PCA and two-way CA, in order to see the differences between the two methods in practice.     

Value-in-context in crowdfunding ecosystems: how context frames value co-creation

The aim of this paper is to analyse the phenomenon of crowdfunding and determine whether it can be considered a service ecosystem, where the context frames innovation through value co-creation. A qualitative, multiple case study approach is used to analyse three platforms and six initiatives in the Spanish arts sector. The findings reveal that crowdfunding can be considered an ecosystem where value-in-context frames seven types of value co-creation, offering a contribution both to ecosystem theory and to the field of co-creation.