Zoocoenological state of microhabitats and its seasonal dynamics in an aquatic macroinvertebrate assembly (Hydrobiological case studies on lake Balaton, No. 1.)

In the years 2002, 2003 and 2004 we collected samples of macroinvertebrates on a total of 36 occasions in Badacsony bay, in areas of open water (in the years 2003 and 2004 reed-grassy) as well as populated by reed (Phragmites australis) and cattail (Typha angustifolia). Samples were taken using a stiff hand net. The sampling site includes three microhabitats differentiated only by the aquatic plants inhabiting these areas. Our data was gathered from processing 208 individual samples. The quantity of macroinvertebrates is represented by biovolume value based on volume estimates. We can identify taxa in abundant numbers found in all water types and ooze; as well as groups associated with individual microhabitats with various aquatic plants. We can observe a notable difference between the years in the volume of invertebrate macrofauna caused by the drop of water level, and the multiplication of submerged macrophytes. There are smaller differences between the samples taken in reeds and cattail stands. In the second half of 2003 – which was a year of drought – the Najas marina appeared in open waters and allowed to support larger quantities of macroinvertebrates. In 2004 with higher water levels, the Potamogeton perfoliatus occurring in the same area has had an even more significant effect. This type of reed-grass may support the most macroinvertebrates during the summer. From the aspect of diversity relations we may suspect different characteristics. The reeds sampling site proved to be the richest, while the cattail microhabitat is close behind, open water (with submerged macrophytes) is the least diverse microhabitat.

Milyen is hát a tőke a 21. században? Megjegyzések Piketty könyvéhez (So what is capital in the 21st century? Notes on Piketty's book)

Ezt az írást Piketty kiváló és fontos könyve inspirálta. A könyvnek nemcsak a címe, hanem számos megfogalmazása is azt a várakozást keltheti, hogy a kapitalista rendszer átfogó elemzése kerül az olvasó kezébe. Ehhez képest a tanulmány szerzőjében hiányérzet támadt. A kapitalista rendszernek számos immanens tulajdonsága, veleszületett hajlama van. Közülük hárommal foglakozik a tanulmány. 1. A kapitalizmus egyik alapvonása a dinamizmus, az innováció, a teremtő rombolás. Nem adhat teljes képet a kapitalizmusról az, aki ezt az alapvetően fontos jelenséget ignorálja. 2. A kapitalizmus óhatatlanul nagyfokú egyenlőtlenséget hoz létre; ezt reformokkal kell enyhíteni, de teljesen nem küszöbölhető ki. 3. A kapitalizmus alapvető jellegzetességei, a magántulajdon és a piaci koordináció dominanciája nagy hatású ösztönzési mechanizmusokat hoznak létre, amelyek mind a tulajdonosokat, mind a vállalatok vezetőit innovációra és hatékony működésre serkentik. Az egyik legfontosabb ösztönző a verseny, különösen az oligopolisztikus verseny. A kapitalista rendszernek e három fontos tendenciája között szoros kölcsönhatás érvényesül. Piketty fő témáját, a jövedelem és a vagyon eloszlását nem lehet jól megérteni, ha a másik két tendenciától elszakítva vizsgáljuk. A tanulmány befejezésül ismerteti a szerző saját értékítéleteit a kapitalista rendszer kedvező és káros, igazságtalan vonásairól. _____ This study was inspired by Piketty s excellent and important book. Its title and numerous statements in it arouse in readers expectations of a comprehensive analysis of capitalism. By comparison the author of this paper felt things were lacking. The capitalist system has numerous immanent traits and innate tendencies, of which the study properties three: 1. One basic feature is dynamism, innovation, and creative destruction. No picture of capitalism can be full if this basic aspect is ignored. 2. Capitalism inevitably brings about a high degree of inequality; this must be eased by reforms, but cannot be entirely overcome. 3. The basic characteristics of capitalism - private ownership and the dominance of market coordination - give rise to strong incentive mechanisms that encourage but owners and enterprise executives to innovate and to cooperate effectively. One of the main incentives is competition, especially oligopolistic competition. There are strong mutual effects among these three important tendencies. It is impossible to understand well Piketty s main subject, the distribution of income and wealth, if it is divorced from the other two tendencies. The study ends with its author s own value judgements on the favourable and harmful, unjust attributes of the capitalist system.

Assignment Games with Externalities

We examine assignment games, wherematched pairs of firms and workers create some monetary value to distribute among themselves and the agents aim to maximize their payoff. In the majority of this literature, externalities - in the sense that a pair’s value depends on the pairing of the others - have been neglected. However, inmost applications a firm’s success depends on, say, the success of its rivals and suppliers. Thus, it is natural to ask how the classical results on assignment games are affected by the introduction of externalities? The answer is – dramatically. We find that (i) a problem may have no stable outcome, (ii) stable outcomes can be inefficient (not maximize total value), (iii) efficient outcomes can be unstable, and (iv) the set of stable outcomes may not form a lattice. We show that stable outcomes always exist if agents are "pessimistic." This is a knife-edge result: there are problems in which the slightest optimism by a single pair erases all stable outcomes.

So what is Capital in the Twenty-First Century? Some notes on Piketty’s book Working paper, forthcoming in Capitalism & Society

This study was inspired by Piketty’s excellent and important book. Its title and numerous statements in it arouse in readers expectations of a comprehensive analysis of capitalism. By comparison the author of this paper felt important aspects were lacking. The capitalist system has numerous immanent traits and innate tendencies, of which the paper takes a closer look at three properties. 1. One basic feature is dynamism, innovation, and creative destruction. No picture of capitalism can be full if this basic aspect is ignored. 2. Capitalism inevitably brings about a high degree of inequality; this must be eased by reforms, but cannot be entirely overcome. 3. The basic characteristics of capitalism – private ownership and the dominance of market coordination – give rise to strong incentive mechanisms that encourage but owners and enterprise executives to innovate and to cooperate effectively. One of the main incentives is competition, especially oligopolistic competition. There are strong mutual effects among these three important tendencies. It is impossible to understand well Piketty’s main subject, the distribution of income and wealth, if it is divorced from the other two tendencies. The study ends with its author’s own value judgements on the favourable and harmful, unjust attributes of the capitalist system.