Market structure and the taxation of international trade

The paper compares non-cooperative commodity taxation under the destination and origin principles under a variety of different assumptions about market structure. We consider a model of international duopoly with either quantity or price competition of firms and either segmented or integrated markets, and a monopolistic competition model with mobile firms. In each setting the international spillovers of tax policy are isolated and evaluated at the Pareto efficient tax rate. The sign of the net spillover, and thus the direction that commodity tax competition will take, depends critically on whether lump-sum taxes are available or commodity taxes must be used to finance the government budget

International Commodity Taxation under Monopolistic Competition

We analyze non-cooperative commodity taxation in a two-country trade model characterized by monopolistic competition and international firm and capital mobility. In this setting, taxes in one country affect foreign welfare through the relocation of mobile firms and through changes in the rents accruing to capital owners. With consumption-based taxation, these fiscal externalities exactly offset each other and the non-cooperative tax equilibrium is Pareto efficient. With production-based taxation, however, there are additional externalities on the foreign tax base and the foreign price level which lead non-cooperative tax rates to exceed their Pareto efficient levels.tax competition, market imperfections, international trade

Market Structure and the Taxation of International Trade

The paper compares non-cooperative commodity taxation under the destination and origin principles under a variety of different assumptions about market structure. We consider a model of international duopoly with either quantity or price competition of firms and either segmented or integrated markets, and a monopolistic competition model with mobile firms. In each setting the international spillovers of tax policy are isolated and evaluated at the Pareto efficient tax rate. The sign of the net spillover, and thus the direction that commodity tax competition will take, depends critically on whether lump-sum taxes are available or commodity taxes must be used to finance the government budget.tax competition, market imperfections, international trade

Market Structure and the Taxation of International Trade

The paper compares non-cooperative commodity taxation under the destination and origin principles under a variety of different assumptions about market structure. We consider a model of international duopoly with either quantity or price competition of firms and either segmented or integrated markets, and a monopolistic competition model with mobile firms. In each setting the international spillovers of tax policy are isolated and evaluated at the Pareto efficient tax rate. The sign of the net spillover, and thus the direction that commodity tax com- petition will take, depends critically on whether lump-sum taxes are available or commodity taxes must be used to finance the government budget.tax competition, market imperfections, international trade

International Commodity Taxation Under Monopolistic Competition

We analyze non-cooperative commodity taxation in a symmetrictwo-country trade model characterized by monopolisticcompetition and international firm and capital mobility. In thissetting, taxes in one country affect foreign welfare through therelocation of mobile firms and through changes in the rentsaccruing to capital owners. With consumption-based taxation,these fiscal externalities exactly offset each other and the non-cooperativetax equilibrium is Pareto efficient. With production-basedtaxation, however, there is an additional externality on theforeign price level which leads non-cooperative tax rates toexceed their Pareto efficient levels.tax competition, market imperfections, internationaltrade

Regional Tax Coordination and Foreign Direct Investment

This paper analyses the effects of a regionally coordinated corporate income tax in a model with three active countries, one of which is not part of the union, and a globally mobile firm. We show that regional tax coordination can lead to two types of welfare gain. First, for investments that would take place in the union in the absence of coordination, a coordinated tax increase can transfer location rents from the firm to the union. Second, by internalising all of the union’s benefits from foreign direct investment, a coordinated tax reduction can attract more welfare-enhancing investment than when member states act in isolation. Depending on which motive dominates, tax levels may thus rise or fall under regional coordination

Metabolic engineering of Halomonas elongata: Ectoine secretion is increased by demand and supply driven approaches

The application of naturally-derived biomolecules in everyday products, replacing conventional synthetic manufacturing, is an ever-increasing market. An example of this is the compatible solute ectoine, which is contained in a plethora of treatment formulations for medicinal products and cosmetics. As of today, ectoine is produced in a scale of tons each year by the natural producer Halomonas elongata. In this work, we explore two complementary approaches to obtain genetically improved producer strains for ectoine production. We explore the effect of increased precursor supply (oxaloacetate) on ectoine production, as well as an implementation of increased ectoine demand through the overexpression of a transporter. Both approaches were implemented on an already genetically modified ectoine-excreting strain H. elongata KB2.13 (ΔteaABC ΔdoeA) and both led to new strains with higher ectoine excretion. The supply driven approach led to a 45% increase in ectoine titers in two different strains. This increase was attributed to the removal of phosphoenolpyruvate carboxykinase (PEPCK), which allowed the conversion of 17.9% of the glucose substrate to ectoine. For the demand driven approach, we investigated the potential of the TeaBC transmembrane proteins from the ectoine-specific Tripartite ATP-Independent Periplasmic (TRAP) transporter as export channels to improve ectoine excretion. In the absence of the substrate-binding protein TeaA, an overexpression of both subunits TeaBC facilitated a three-fold increased excretion rate of ectoine. Individually, the large subunit TeaC showed an approximately five times higher extracellular ectoine concentration per dry weight compared to TeaBC shortly after its expression was induced. However, the detrimental effect on growth and ectoine titer at the end of the process hints toward a negative impact of TeaC overexpression on membrane integrity and possibly leads to cell lysis. By using either strategy, the ectoine synthesis and excretion in H. elongata could be boosted drastically. The inherent complementary nature of these approaches point at a coordinated implementation of both as a promising strategy for future projects in Metabolic Engineering. Moreover, a wide variation of intracelllular ectoine levels was observed between the strains, which points at a major disruption of mechanisms responsible for ectoine regulation in strain KB2.13.This work has been funded by the German Federal Ministry of Education and Research (BMBF) through project HOBBIT (031B03)

Adaptation to Varying Salinity in Halomonas elongata: Much More Than Ectoine Accumulation

The halophilic γ-proteobacterium Halomonas elongata DSM 2581 T thrives at salt concentrations well above 10 % NaCl (1.7 M NaCl). A well-known osmoregulatory mechanism is the accumulation of the compatible solute ectoine within the cell in response to osmotic stress. While ectoine accumulation is central to osmoregulation and promotes resistance to high salinity in halophilic bacteria, ectoine has this effect only to a much lesser extent in non-halophiles. We carried out transcriptome analysis of H. elongata grown on two different carbon sources (acetate or glucose), and low (0.17 M NaCl), medium (1 M), and high salinity (2 M) to identify additional mechanisms for adaptation to high saline environments. To avoid a methodological bias, the transcripts were evaluated by applying two methods, DESeq2 and Transcripts Per Million (TPM). The differentially transcribed genes in response to the available carbon sources and salt stress were then compared to the transcriptome profile of Chromohalobacter salexigens, a closely related moderate halophilic bacterium. Transcriptome profiling supports the notion that glucose is degraded via the cytoplasmic Entner-Doudoroff pathway, whereas the Embden-Meyerhoff-Parnas pathway is employed for gluconeogenesis. The machinery of oxidative phosphorylation in H. elongata and C. salexigens differs greatly from that of non-halophilic organisms, and electron flow can occur from quinone to oxygen along four alternative routes. Two of these pathways via cytochrome bo' and cytochrome bd quinol oxidases seem to be upregulated in salt stressed cells. Among the most highly regulated genes in H. elongata and C. salexigens are those encoding chemotaxis and motility proteins, with genes for chemotaxis and flagellar assembly severely downregulated at low salt concentrations. We also compared transcripts at low and high-salt stress (low growth rate) with transcripts at optimal salt concentration and found that the majority of regulated genes were down-regulated in stressed cells, including many genes involved in carbohydrate metabolism, while ribosome synthesis was up-regulated, which is in contrast to what is known from non-halophiles at slow growth. Finally, comparing the acidity of the cytoplasmic proteomes of non-halophiles, extreme halophiles and moderate halophiles suggests adaptation to an increased cytoplasmic ion concentration of H. elongata. Taken together, these results lead us to propose a model for salt tolerance in H. elongata where ion accumulation plays a greater role in salt tolerance than previously assumed