'Klin'-ing Up: Effects of Polish Tax Reforms on Those In and on Those Out

In 2007 and 2008 Polish governments introduced a series of reforms which led to a substantial reduction in the tax "wedge" (in Polish: "klin") on labour. We show that when considered together the package of introduced reforms brought much greater reductions in the tax burden compared to a widely discussed 15% "flat tax". In the analysis we show the effects of the reforms both for the employed and for the non-employed populations. The latter analysis is done in such a way as to account for the entire (simulated) distribution of wages of the non-employed and shows interesting differences between the effects of reforms on employed and non-employed individuals. We argue that to fully appreciate the effect of reductions in labour taxation it is important to bear in mind that one of the reasons for introducing them is to make employment more likely for those who currently do not work. Given the extent of the reductions in the "klin" it is somewhat surprising that so far so little attention has been given to the recent Polish reforms.work incentives, tax wedge, labour costs, employment

The Relaxed Edge-Coloring Game and \u3cem\u3ek\u3c/em\u3e-Degenerate Graphs

The (r, d)-relaxed edge-coloring game is a two-player game using r colors played on the edge set of a graph G. We consider this game on forests and more generally, on k-degenerate graphs. If F is a forest with ∆(F) = ∆, then the first player, Alice, has a winning strategy for this game with r = ∆ − j and d ≥ 2j + 2 for 0 ≤ j ≤ ∆ − 1. This both improves and generalizes the result for trees in [10]. More broadly, we generalize the main result in [10] by showing that if G is k-degenerate with ∆(G) = ∆ and j ∈ [∆ + k − 1], then there exists a function h(k, j) such that Alice has a winning strategy for this game with r = ∆ + k − j and d ≥ h(k, j)

Count Your Hours: Returns to Education in Poland

We show how significant may be the difference in the estimated returns to education in Poland conditional on the measure of wages used and the estimation approach applied. Combining information from two different Polish surveys from 2005 and taking advantage of the Polish microsimulation model (SIMPL) we demonstrate how different the results can be depending on whether we use net or gross, and monthly or hourly wages, and show how important selection correction is for the conclusion. While there are several papers examining the wage equation in Poland, so far none of them has provided a comprehensive analysis of the effects of using different methods and the issue of selection-correction in the estimation of the wage equation in Poland has not been examined in detail. Annual rates of return to university education for men vary from 6.7% to 9.7% and for women from 8.0% to 13.4% when we compare results using net monthly wages without correcting for labor market selection to those from a selection corrected specification using gross hourly wages. We also demonstrate that simple linear estimation performs relatively well for men in comparison to our preferred selection corrected estimation, while using family demographics as exclusion restrictions seems to be the "second best" in the case of the wage equation estimation for women.returns to education, wage equation, selection models, instrumental variables

Near threshold kaon-kaon interaction in the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma

Strong interactions between pairs of the K+ K- and K0 K0bar mesons can be studied in radiative decays of phi(1020) mesons. We present a theoretical model of the reactions e+ e- --> phi --> K+ K- gamma and e+ e- --> phi --> K0 K0bar gamma. The K+ K- and K0 K0bar effective mass dependence of the differential cross sections is derived. The total cross sections and the branching fractions for the two radiative phi decays are calculated.Comment: 4 pages, 3 figures, contribution to 15th International Workshop on Meson Physics, Cracow, Poland, 7th - 12th June 201

Game-based communication in Network Control Systems

Network based Control Systems (NCSs) are more and more often selected in designing distributed control systems due to both economic and practical reasons. Today designs of NCSs frequently involve the non-expensive wireless communication instead of traditional wired links. Such systems are usually calledWireless Sensor Networks (WSNs) and are used for many other purposes as well. While convenient in installation and management, wireless links are susceptible to noise and not very reliable. While common approach of data delivery relies on routing (proactive or reactive), this paper presents a different approach to designing wireless NCSs. In the proposed approach every node takes an independent decision as a result of a game between the nodes. Unlike the routing solutions, the nodes never create any path, and even have no knowledge concerning network topology

'Klin'-ing up: effects of Polish tax reforms on those in and on those out

In 2007 and 2008 Polish governments introduced a series of reforms which led to a substantial reduction in the tax "wedge" (in Polish: "klin") on labour. The mean ATR on total labour cost was reduced from 41.6% to 34.0%. We show that when considered together the package of introduced reforms brought much greater reductions in the tax burden compared to a widely discussed 15% "flat tax". In the analysis we show the effects of the reforms both for the employed and for the non-employed populations. The latter analysis is done in such a way as to account for the entire (simulated) distribution of wages of the non-employed and shows interesting differences between the effects of reforms on employed and non-employed individuals. We argue that to fully appreciate the effect of reductions in labour taxation it is important to bear in mind that one of the reasons for introducing them is to make employment more likely for those who currently do not work. Given the extent of the reductions in the "klin" it is somewhat surprising that so far so little attention has been given to the recent Polish reforms.Work incentives, tax wedge, labour costs, employment

Functional expression of horseradish peroxidase in Saccharomyces cerevisiae and Pichia pastoris

The ability to engineer proteins by directed evolution requires functional expression of the target polypeptide in a recombinant host suitable for construction and screening libraries of enzyme variants. Bacteria and yeast are preferred, but eukaryotic proteins often fail to express in active form in these cells. We have attempted to resolve this problem by identifying mutations in the target gene that facilitate its functional expression in a given recombinant host. Here we examined expression of HRP in Saccharomyces cerevisiae. Through three rounds of directed evolution by random point mutagenesis and screening, we obtained a 40-fold increase in total HRP activity in the S.cerevisiae culture supernatant compared with wild-type, as measured on ABTS [2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)] (260 units/l/OD_(600)). Genes from wild-type and two high-activity clones were expressed in Pichia pastoris, where the total ABTS activity reached 600 units/l/OD_(600) in shake flasks. The mutants show up to 5.4-fold higher specific activity towards ABTS and 2.3-fold higher specific activity towards guaiacol

Substrate Range and Genetic Analysis of Acinetobacter Vanillate Demethylase

An Acinetobacter sp. genetic screen was used to probe structure-function relationships in vanillate demethylase, a two-component monooxygenase. Mutants with null, leaky, and heat-sensitive phenotypes were isolated. Missense mutations tended to be clustered in specific regions, most of which make known contributions to catalytic activity. The vanillate analogs m-anisate, m-toluate, and 4-hydroxy-3,5-dimethylbenzoate are substrates of the enzyme and weakly inhibit the metabolism of vanillate by wild-type Acinetobacter bacteria. PCR mutagenesis of vanAB, followed by selection for strains unable to metabolize vanillate, yielded mutant organisms in which vanillate metabolism is more strongly inhibited by the vanillate analogs. Thus, the procedure opens for investigation amino acid residues that may contribute to the binding of either vanillate or its chemical analogs to wild-type and mutant vanillate demethylases. Selection of phenotypic revertants following PCR mutagenesis gave an indication of the extent to which amino acid substitutions can be tolerated at specified positions. In some cases, only true reversion to the original amino acid was observed. In other examples, a range of amino acid substitutions was tolerated. In one instance, phenotypic reversion failed to produce a protein with the original wild-type sequence. In this example, constraints favoring certain nucleotide substitutions appear to be imposed at the DNA level