Global-scale modeling of nitrogen balances at the soil surface

This paper provides global terrestrial surface balances of nitrogen (N) at a resolution of 0.5 by 0.5 degree for the years 1961, 1995 and 2050 as simulated by the model WaterGAP-N. The terms livestock N excretion (Nanm), synthetic N fertilizer (Nfert), atmospheric N deposition (Ndep) and biological N fixation (Nfix) are considered as input while N export by plant uptake (Nexp) and ammonia volatilization (Nvol) are taken into account as output terms. The different terms in the balance are compared to results of other global models and uncertainties are described. Total global surface N surplus increased from 161 Tg N yr-1 in 1961 to 230 Tg N yr-1 in 1995. Using assumptions for the scenario A1B of the Special Report on Emission Scenarios (SRES) of the International Panel on Climate Change (IPCC) as quantified by the IMAGE model, total global surface N surplus is estimated to be 229 Tg N yr-1 in 2050. However, the implementation of these scenario assumptions leads to negative surface balances in many agricultural areas on the globe, which indicates that the assumptions about N fertilizer use and crop production changes are not consistent. Recommendations are made on how to change the assumptions about N fertilizer use to receive a more consistent scenario, which would lead to higher N surpluses in 2050 as compared to 1995

The "champagne tower" of science publishing

This article discusses the hierarchical nature of science publishing, whereby journals are organized in tiers with the most prestigious elite journals at the top (Cell, Nature, Science), and lowest-ranked journals at the bottom. When rejected from the top-tier journals, authors usually aim for a lower tier of journals, with some choosing smaller, specialist journals for the outlet of their work. Recently, however, a different mechanism of cascading the papers down the hierarchy of journals has become popular, i.e., editors arrange to pass the rejected papers, with the authors’ permission, to their “sister journals” bearing the same brand. These transfer arrangements may be seen beneficial for the authors, as they reduce the publication time, but they also pose difficulties for smaller specialist journals that lose their share of the market and experience a fall in manuscript submissions

The economic integration of Germany

In the integration of the two Germanies two countries will be united which differ widely in their institutional and constitutional arrangements as well as in their monetary systems and real economic conditions. Integration therefore means - harmonization of the institutional systems, - introduction of a common currency and a unified monetary policy, and - adjustment in the real economies. In the process of integration, these three aspects of institutional harmonization, establishing a single monetary policy and bringing the real economic conditions closer to each other will overlap. The final state of the integration process is a fully integrated economic union. In the commodity markets, the law of one price will govern for tradeables. The prices for non-tradeables such as housing and some services will differ among regions. In the factor markets, one price will prevail for any given factor that is completely mobile. Interest rates and the marginal productivity of capital will be identical everywhere. However, prices of immobile factors of production such as land and the environment will differ from region to region. Labor will be in an intermediate position. Insofar as labor is completely mobile, real wages tend to equalize; they can, however, be different when the costs of living vary over space. When labor is only partly mobile and when preferences for specific locations exist, real wages may be more differentiated. On the monetary side, there will be only one currency whose value is determined by the money supply of one central bank. The social security systems will be harmonized. The state, including the provision of public goods and the tax system, will be homogeneous, notwithstanding federal elements. Finally, the firms and the sectorial structure in the economic union will have adjusted to the new conditions, and the German Democratic Republic (GDR) will have caught up in income per head. --

The Introduction of New Product Qualities by Incumbent Firms: Market Proliferation versus Cannibalization

This study analyzes the optimal provision of goods in a market characterized by vertical product differentiation. We consider a duopoly model in which incumbents may introduce a new product with certain quality, and decide whether to keep or to withdraw the existing product from the market. We find that the strategic and cannibalization effects dominate, such that no room is left for discrimination among consumers. The innovator always withdraws the existing product from the market, in order to reduce price competition and to avoid cannibalizing its new product demand. In contrast to horizontally differentiated markets, firms are better off not to offer a range or interval of product qualities in vertically differentiated markets. Hence, firms fare better, despite offering a smaller variety of goods. ZUSAMMENFASSUNG - (Die Einfuehrung neuer Qualitaetsprodukte von Unternehmen: Marktnischenbesetzung versus Kannibalisierung der Nachfrage) Diese Studie analysiert das optimale Angebot von Guetern, die sich in der Qualitaet untescheiden. Wir betrachten ein Modell, in dem zwei insaessige Unternehmen neue Produkte mit unterschiedlicher Qualitaet in den Markt einfuehren koennen. Zudem koennen die Innovatoren entscheiden, ob ihre existierenden Produkte weiterhin im Markt angeboten oder abgezogen werden sollen. Wir zeigen, dass strategische Effekte und Kannibalisierungseffekte keine Diskriminierung zwischen den Konsumenten zulassen. Der Innovator zieht das existierende Produkt immer aus dem Markt, um einen erhoehten Preiswettbewerb und eine Kannibilisierung der eigenen Nachfrage zu vermeiden. Im Gegensatz zu horizontal differenzierten Maerkten, stellen sich Unternehmen in vertikal differenzierten Maerkten besser, eine geringere Produktvielfalt anzubieten.Asymmetric Firms, Cannibalization, Market Proliferation, New Product Introduction, Product Innovation, Vertical Product Differentiation.

Labor productivities and labor costs in Euroland

The paper presents labor productivities in the member countries of Euroland. The result is that there is quite a divergence in labor productivities (per head) in the European Monetary Union. The Netherlands and Italy reach 85 percent of the West German level, Spain 62 and Portugal 35. This implies that labor costs have to be differentiated substantially between the euro countries. Labor costs relative to the West German level are also calculated. The paper analyzes the implication of diverging labor productivities for wage policy and for the financing of the social security systems in the European Monetary Union.

Multiproduct Competition, Learning by Doing and Price-Cost Margins over the Product Life Cycle: Evidence from the DRAM Industry

In this study we specify and estimate a structural model of multiproduct firms for the semiconductor industry. In addition, we explicitly consider dynamics over the product life cycle. We find that these two aspects have important implications and provide evidence that (i) Spillover and Economies of Scale effects are lower for multiproduct firms than for single product firms, whereas Learning by Doing effects are slightly higher. We also find that firms follow an intertemporal output strategy. Furthermore, we provide evidence that, once multiproduct firms are introduced, firms behave as if in perfect competition. A single product specification leads to firms behaving even "softer" than Cournot players in the product market. We show that (ii) Learning by Doing, Economies of Scale, and Spillover effects vary over the product cycle. Learning by Doing effects are higher at the end of the life cycle when new production technologies are developed. Economies of Scale are increasing and become smaller (larger) over the life cycle for multiproduct (single product) firms. We specify a dynamic theoretical model and estimate a dynamic structural model by using quarterly firm-level output and costs data as well as industry prices for the Dynamic Random Access Memory (DRAM) industry from 1974 to 1996. ZUSAMMENFASSUNG - (Mehrproduktwettbewerb, Learning by Doing und Price-Cost Margins über den Produktlebenszyklus: Beweis aus der DRAM Industrie) In dieser Studie spezifizieren und schätzen wir ein strukturelles Modell von Mehrproduktunternehmen in der Halbleiterindustrie. Zusätzlich berücksichtigen wir explizit die Dynamik über den Produktlebenszyklus. Unsere Ergebnisse zeigen, daß diese beiden Aspekte gravierende Auswirkungen besitzen. Wir zeigen, daß (i) Spillovers und Skalenerträge für Mehrproduktunternehmen geringer sind als für Einzelproduktunternehmen, wogegen Lerneffekte geringfügig größer ausfallen. Unsere Ergebnisse bestätigen auch, daß Unternehmen eine intertemporale Outputstrategie verfolgen. Weiterhin wird gezeigt, daß sich Mehrproduktunternehmen im perfekten Wettbewerb befinden, wobei sich Einzelproduktunternehmen ähnlich wie Cournot Spieler verhalten. Wir zeigen, daß (ii) Lerneffekte, Skalenerträge und Spillovereffekte über den Produktlebenszyklus variieren. Lerneffekte sind am Ende des Produktlebenszyklus größer, wenn neue Produkttechnologien entwickelt werden. Skalenerträge sind zunehmend und nehmen für Mehrproduktunternehmen (Einzelproduktunternehmen) im Ausmaß zum Ende des Produktlebenszyklus ab (zu). Wir spezifizieren ein dynamisches theoretisches Modell und schätzen ein dynamisches strukturelles Modell unter Verwendung von vierteljährlichen Output- und Kostendaten auf Unternehmensebene, von der .Dynamic Random Access Memory. (DRAM) Industrie für den Zeitraum von 1974 bis 1996.Multiproduct Competition; Learning by Doing; Product Life Cycle; Economies of Scale; Spillovers; Semiconductor; Process Innovation

A Schumpeterian model of growth in the world economy : some notes on a new paradigm in international economics.

Exportinduziertes Wachstum; Technischer Fortschritt; Theorie;