The impact of asymmetry of information and different ambiguity reactions on insurance demand

We extend the model of ex-ante asymmetric information in the insurance market of Stiglitz (1977) by incorporating consumers’ reactions to uncertainty. Specifically, we assume that some agents are able to assign a precise probability measure to the event of loss (Savage, 1954), whilst others are not. The behavior of the latter group complies either with proba-bilistic sophistication or ambiguity aversion as modeled by maxmin expected utility (Gilboa and Schmeidler, 1989). When the former class exhibits sufficient pessimism, these two types are virtually indistinguishable when exposed to rare hazards. Thus, pooling constitutes as an optimal solution to the problem of the monopolist

Oceanic heat advection to the Arctic in the last Millennium

EGU2011-8738 At present, the Arctic is responding faster to global warming than most other areas on earth, as indicated by rising air temperatures, melting glaciers and ice sheets and a decline of the sea ice cover. As part of the meridional overturning circulation which connects all ocean basins and influences global climate, northward flowing Atlantic Water is the major means of heat and salt advection towards the Arctic where it strongly affects the sea ice distribution. Records of its natural variability are critical for the understanding of feedback mechanisms and the future of the Arctic climate system, but continuous historical records reach back only ca. 150 years. To reconstruct the history of temperature variations in the Fram Strait Branch of the Atlantic Current we analyzed a marine sediment core from the western Svalbard margin. In multidecadal resolution the Atlantic Water temperature record derived from planktic foraminifer associations and Mg/Ca measurements shows variations corresponding to the well-known climatic periods of the last millennium (Medieval Climate Anomaly, Little Ice Age, Modern/Industrial Period). We find that prior to the beginning of atmospheric CO2 rise at ca. 1850 A.D. average summer temperatures in the uppermost Atlantic Water entering the Arctic Ocean were in the range of 3-4.5°C. Within the 20th century, however, temperatures rose by ca. 2°C and eventually reached the modern level of ca. 6°C. Such values are unprecedented in the 1000 years before and are presumably linked to the Arctic Amplification of global warming. Taking into account the ongoing rise of global temperatures, further warming of inflowing Atlantic Water is expected to have a profound influence on sea ice and air temperatures in the Arctic

AMF species do matter: Rhizophagus irregularis and Funneliformis mosseae affect healthy and PVY-infected Solanum tuberosum L. in a different way

Arbuscular mycorrhizal fungi (AMF) were documented to positively influence plant growth and yield, which is extremely important for the production of many crops including potato. However, the nature of the interaction between arbuscular mycorrhiza and plant virus that share the same host is not well characterized. In this study, we examined the effect of different AMF, Rhizophagus irregularis and Funneliformis mosseae, on healthy and potato virus Y (PVY)-infected Solanum tuberosum L. The analyses conducted included the measurement of potato growth parameters, oxidative stress indicators, and photosynthetic capacity. Additionally, we evaluated both the development of AMF in plant roots and the virus level in mycorrhizal plants. We found that two AMF species colonized plant roots to varying degrees (ca. 38% for R. irregularis vs. 20% for F. mosseae). Rhizophagus irregularis had a more positive effect on potato growth parameters, causing a significant increase in the total fresh and dry weight of tubers, along with virus-challenged plants. Furthermore, this species lowered hydrogen peroxide levels in PVY-infected leaves and positively modulated the levels of nonenzymatic antioxidants, i.e., ascorbate and glutathione in leaves and roots. Finally, both fungal species contributed to reduced lipid peroxidation and alleviation of virus-induced oxidative damage in plant organs. We also confirmed an indirect interaction between AMF and PVY inhabiting the same host. The two AMF species seemed to have different abilities to colonize the roots of virus-infected hosts, as R. irregularis showed a stronger drop in mycorrhizal development in the presence of PVY. At the same time, arbuscular mycorrhiza exerted an effect on virus multiplication, causing increased PVY accumulation in plant leaves and a decreased concentration of virus in roots. In conclusion, the effect of AMF-plant interactions may differ depending on the genotypes of both symbiotic partners. Additionally, indirect AMF-PVY interactions occur in host plants, diminishing the establishment of arbuscular mycorrhiza while changing the distribution of viral particles in plants

Changepoint Detection in Noisy Data Using a Novel Residuals Permutation-Based Method (RESPERM): Benchmarking and Application to Single Trial ERPs

An important problem in many fields dealing with noisy time series, such as psychophysiological single trial data during learning or monitoring treatment effects over time, is detecting a change in the model underlying a time series. Here, we present a new method for detecting a single changepoint in a linear time series regression model, termed residuals permutation-based method (RESPERM). The optimal changepoint in RESPERM maximizes Cohen’s effect size with the parameters estimated by the permutation of residuals in a linear model. RESPERM was compared with the SEGMENTED method, a well-established and recommended method for detecting changepoints, using extensive simulated data sets, varying the amount and distribution characteristics of noise and the location of the change point. In time series with medium to large amounts of noise, the variance of the detected changepoint was consistently smaller for RESPERM than SEGMENTED. Finally, both methods were applied to a sample dataset of single trial amplitudes of the N250 ERP component during face learning. In conclusion, RESPERM appears to be well suited for changepoint detection especially in noisy data, making it the method of choice in neuroscience, medicine and many other fields.Peer Reviewe

Kwota wolna od opodatkowania sprawiedliwość podatkowa

Celem artykułu jest analiza instytucji kwoty wolnej od podatku, stanowiącej minimum podatkowe, poniżej którego wartość osiągniętego dochodu nie podlega opodatkowaniu, przez pryzmat zasad sprawiedliwości podatkowej oraz sprawiedliwości w ujęciu polityki społecznej. W artykule dokonano zdefiniowania kwoty wolnej od opodatkowania na pod‑ stawie przeglądu literatury oraz ustalenia jej miejsca w katalogu funkcji pełnionych przez prawo podatkowe. Wyniki badania opinii pozwoliły natomiast na dokonanie analizy, w jaki sposób respondenci deklarują ocenę kwoty wolnej od podatku. Wnioski z prze‑ prowadzonych analiz mogą stanowić podstawę dalszych badań nad sprawiedliwością opodatkowania

Społeczne aspekty opodatkowania – progresywność opodatkowania

Celem artykułu jest analiza progresywnego sposobu opodatkowania wynagrodzeń w odniesieniu do zasad sprawiedliwości podatkowej oraz sprawiedliwości w ujęciu polityki społecznej. W artykule, na podstawie przeglądu literatury, zdefiniowano zasadę progresywności oraz dokonano jej analizy przez pryzmat zasad podatkowych. Wyniki badań opinii pozwoliły natomiast na przeanalizowanie, w jaki sposób respondenci deklarują swoją ocenę ukształtowania systemu opodatkowania według skali progresywnej. Analiza przeprowadzonych badań pozwala na skonstruowanie wniosków w zakresie dalszych rozważań nad sprawiedliwością opodatkowania

Board meetings and bank performance in Africa

This study examines the relationship between a board meeting and banks performance in Africa. This paper provides insight on this question after taking into account the endogeneity of the relationship between board meetings and performance. Specifically, we use the GMM technique and a sample of 635 banks from 48 countries in Africa between 2000 to 2016 to test our hypothesis and found that more board meetings, averagely 6, reduce banks’ performance in sub-Sahara Africa. In the Northern Africa context, with an average board meeting of 7.68, however, we document a positive and significant association between a board meeting and bank performance. Our result suggests that fewer board meeting enhances the shareholder value of Banks in Sub-Sahara Africa but not their counterparts in North Africa. Our paper provides insights to policymakers responsible for improving the governance mechanisms in African banks

Opinie polskich pracowników o wynagrodzeniu minimalnym i ich konteksty w mediach

Celem artykułu jest przedstawienie opinii polskich pracowników dotyczących: minimalnego wynagrodzenia w odniesieniu do roli tego wynagrodzenia jako instrumentu polityki społecznej, treści medialnych o relacji pracownika z pracodawcą oraz poczucia sprawiedliwości społecznej. Analiza naświetla minimalne wynagrodzenie pod kątem sytuacji prawnej, aspektów polityki społecznej oraz narracji pojawiających się w mediach. W artykule zostały przedstawione wyniki badania opinii przeprowadzonego na reprezentatywnej grupie Polaków. Na podstawie ich analizy można wnioskować, że minimalne wynagrodzenie w opinii respondentów powinno być ukształtowane na poziomie pozwalającym przeżyć, co może rodzić pytania o jego indywidualizację i dywersyfikację w zależności od indywidualnych cech pracującego

Factors Affecting Women’s Intention to Lead Family Businesses in Mexico

The purpose of this study is to establish the prevalence of barriers to women’s leadership in the family business in terms of invisibility, the glass ceiling effect, and sexism. We conduct eight semi-structured interviews with women holding leading managerial roles in family businesses in Mexico to identify the factors that impede/facilitate their involvement. We apply the theory of planned behavior (TPB) in order to determine how these factors support/constrain women in their roles. We find that some factors and circumstances are critical for women to achieve an important leadership role in the family business. These factors entail levels of education and experience, the extent to which women participate in strategic decision making and governance of the firm, as well as the support of the company’s founder and other family members for these women’s efficacy and self-esteem. These results challenge some of the extant findings in the literature, thus enriching the current perspectives on the leadership role of women in family firms. Moreover, this research is the first attempt to analyze impediments to women under the TPB perspective as well as one of the few studies conducted on the topic in Latin America, specifically in Mexico