The Optimal Distribution of the Tax Burden over the Business Cycle

This paper analyses optimal income taxes over the business cycle under a balanced-budget restriction, for low, middle and high income households. A model incorporating capital-skill complementarity in production and differential access to capital and labour markets is developed to capture the cyclical characteristics of the US economy, as well as the empirical observations on wage (skill premium) and wealth inequality. We .nd that the tax rate for high income agents is optimally the least volatile and the tax rate for low income agents the least countercyclical. In contrast, the path of optimal taxes for the middle income group is found to be very volatile and counter-cyclical. We further find that the optimal response to output-enhancing capital equipment technology and spending cuts is to increase the progressivity of income taxes. Finally, in response to positive TFP shocks, taxation becomes more progressive after about two years

Tax smoothing in a business cycle model with capital-skill complementarity

This paper undertakes a normative investigation of the quantitative properties of optimal tax smoothing in a business cycle model with state contingent debt, capital-skill complementarity and endogenous skill acquisition under technology and public expenditure shocks. We find that skilled and unskilled labour tax smoothing maintain quantitatively under externalities and exogenous shocks in skill acquisition, as well as when the relative skill supply is exogenously determined. We further find that the government finds it optimal to reduce both the size of the wedge between the marginal rates of substitution and transformation in skill attainment in the long-run and the standard deviation of this wedge over the business cycle. This is achieved by subsidising skill creation and taxing both types of labour income

Chronological Age Affects MSC Senescence In Vitro-A Systematic Review.

The use of mesenchymal stromal cells (MSCs) in regenerative medicine and tissue engineering is well established, given their properties of self-renewal and differentiation. However, several studies have shown that these properties diminish with age, and understanding the pathways involved are important to provide regenerative therapies in an ageing population. In this PRISMA systematic review, we investigated the effects of chronological donor ageing on the senescence of MSCs. We identified 3023 studies after searching four databases including PubMed, Web of Science, Cochrane, and Medline. Nine studies met the inclusion and exclusion criteria and were included in the final analyses. These studies showed an increase in the expression of p21, p53, p16, ROS, and NF-κB with chronological age. This implies an activated DNA damage response (DDR), as well as increased levels of stress and inflammation in the MSCs of older donors. Additionally, highlighting the effects of an activated DDR in cells from older donors, a decrease in the expression of proliferative markers including Ki67, MAPK pathway elements, and Wnt/β-catenin pathway elements was observed. Furthermore, we found an increase in the levels of SA-β-galactosidase, a specific marker of cellular senescence. Together, these findings support an association between chronological age and MSC senescence. The precise threshold for chronological age where the reported changes become significant is yet to be defined and should form the basis for further scientific investigations. The outcomes of this review should direct further investigations into reversing the biological effects of chronological age on the MSC senescence phenotype

External financing, growth and capital structure

The study focuses on Greek non-financial firms listed on the Athens Exchange in the period 1998-2002 and shows that only a small fraction of these firms were in a position to finance their growth by exclusively using internal resources with the findings varying depending on the firms’ size. For those firms that had to resort to external financing, short-term financing was favoured compared to long-term financing. While the need for short-term debt did not differ significantly between small and large firms, the need for additional long-term debt was clearly greater for large firms. As regards the determinants of capital structure(as measured by the total-debt-to-assets ratio), the effect of profitability is negative and statistically significant supporting the “pecking order” theory. As expected, tangible assets and firm size have a positive and statistically significant effect on the total debt-to-assets ratio, while short-term assets have the anticipated positive effect only on short-term external financing

The optimal distribution of the tax burden over the business cycle

This paper analyzes optimal capital and labor income taxation for households differentiated by labor skill, income, and wealth, under a balanced government budget, over the business cycle. A model incorporating capital–skill complementarity in production and differential access to labor and capital markets is developed to capture the cyclical characteristics of the US economy, as well as the empirical observations on wage (skill premium) and wealth inequality. We find that optimal taxes for middle-income households are more volatile than the remaining taxes. Moreover, the government re-allocates the total tax burden in bad times so that the share of total tax revenue paid by middle-income households rises. This share also rises for low-income households but by significantly less, whereas the tax share for skilled households falls

External financing, growth and capital structure

The study focuses on Greek non-financial firms listed on the Athens Exchange in the period 1998-2002 and shows that only a small fraction of these firms were in a position to finance their growth by exclusively using internal resources with the findings varying depending on the firms’ size. For those firms that had to resort to external financing, short-term financing was favoured compared to long-term financing. While the need for short-term debt did not differ significantly between small and large firms, the need for additional long-term debt was clearly greater for large firms. As regards the determinants of capital structure(as measured by the total-debt-to-assets ratio), the effect of profitability is negative and statistically significant supporting the “pecking order” theory. As expected, tangible assets and firm size have a positive and statistically significant effect on the total debt-to-assets ratio, while short-term assets have the anticipated positive effect only on short-term external financing

Appraising the causal role of risk factors in coronary artery disease and stroke:A systematic review of Mendelian Randomization studies

BACKGROUND Mendelian randomization (MR) offers a powerful approach to study potential causal associations between exposures and health outcomes by using genetic variants associated with an exposure as instrumental variables. In this systematic review, we aimed to summarize previous MR studies and to evaluate the evidence for causality for a broad range of exposures in relation to coronary artery disease and stroke. METHODS AND RESULTS MR studies investigating the association of any genetically predicted exposure with coronary artery disease or stroke were identified. Studies were classified into 4 categories built on the significance of the main MR analysis results and its concordance with sensitivity analyses, namely, robust, probable, suggestive, and insufficient. Studies reporting associations that did not perform any sensitivity analysis were classified as nonevaluable. We identified 2725 associations eligible for evaluation, examining 535 distinct exposures. Of them, 141 were classified as robust, 353 as probable, 110 as suggestive, and 926 had insufficient evidence. The most robust associations were observed for anthropometric traits, lipids, and lipoproteins and type 2 diabetes with coronary artery; disease and clinical measurements with coronary artery disease and stroke; and thrombotic factors with stroke. CONCLUSIONS Despite the large number of studies that have been conducted, only a limited number of associations were supported by robust evidence. Approximately half of the studies reporting associations presented an MR sensitivity analysis along with the main analysis that further supported the causality of associations. Future research should focus on more thorough assessments of sensitivity MR analyses and further assessments of mediation effects or nonlinearity of associations