Collusion with private and aggregate information

This paper considers three linear asymmetric oligopoly models with (i) a representative consumer, (ii) horizontal differentiation and (iii) vertical differentiation. We show that firms could maximize the joint-profit only based on private and aggregate information. They can choose the “correct“ colluding prices without knowing the demand or profit function. The collusive outcome is a natural focal point despite firms are asymmetric. Collusion can be incentive compatible even though individual actions (prices) are not observed. -- Der Beitrag untersucht drei linear asymmetrische Oligopol-Modelle mit (i) einem repräsentativen Verbraucher, (ii) horizontaler Differenzierung und (iii) vertikaler Differenzierung. Es wird gezeigt, daß Firmen in der Lage sind, den Gesamtprofit allein auf der Grundlage privater und gemeinschaftlicher Information zu maximieren. Sie können zur „richtigen“ Absprache des Preises gelangen, ohne die Nachfrage- oder Gewinn-Funktion zu kennen. Die Absprache stellt einen natürlichen Gleichgewichtspunkt dar, ungeachtet asymmetrischer Verhältnisse. Die Absprache kann anreizkompatibel sein, auch wenn individuelle Aktionen (Preise) nicht beobachtet werden.

Incentives and welfare effect of sharing firm-specific information

This paper studies the incentives and the welfare effect of sharing firm-specific information in asymmetric Cournot and Bertrand oligopoly with mixed substitute and complement goods. Revealing firm-specific cost information is the dominant strategy in Cournot oligopoly, while concealing is so in Bertrand oligopoly. Such information sharing always hurts consumers. It increases social welfare in quantity competition and reduces social welfare in price competition. The results of sharing firm-specific cost information in Cournot oligopoly also apply to sharing firm-specific demand information in Cournot and Bertrand competition. -- In diesem Beitrag werden Anreize und Wohlfahrtseffekte des Austauschs von unternehmensspezifischer Information in einem asymmetrischen Cournot- und Bertrand- Oligopol mit einer Mischung von substitutiven und komplementären Gütern untersucht. Das Aufdecken unternehmensspezifischer Kosteninformation ist die dominante Strategie im Cournot-Oligopol, während im Bertrand-Oligopol diese Information vorenthalten wird. Derartiger Informationsaustausch geht immer zu Lasten der Konsumenten. Er erhöht die soziale Wohlfahrt im Mengenwettbewerb und verringert die soziale Wohlfahrt im Preiswettbewerb. Das Ergebnis des Austauschs unternehmensspezifischer Kosteninformation im Cournot-Oligopol läßt sich auch auf den unternehmensspezifischen Austausch von Nachfrageinformation im Cournot- und Bertrand-Wettbewerb anwenden.

Learning by doing, spillover and shakeout in monoplastic competition

This paper studies the impact of learning by doing on shakeouts in monopolistic competition. Firms have different initial costs and set prices to maximize current profits in each period. Although all firms make positive profits at the beginning and grow for a certain period of time, shakeouts may occur as costs are reduced through learning by doing and spillovers. We give a necessary condition for shakeouts in terms of the relative effectiveness of proprietary learning and the industry-wide learning. Given this condition, shakeouts are more likely to occur when the learning potential is large, the market is small, the proprietary learning is effective and spillovers are weak. In the absence of any strategic learning or predatory pricing, learning by doing can create significant market barriers. -- In diesem Aufsatz werden die Auswirkungen von Lerneffekten durch (Produktions-)erfahrung auf Marktaustritte (sog. „shakeouts“) im Kontext monopolistischer Konkurrenz untersucht. Unternehmen haben unterschiedliche Anfangskosten und maximieren ihre laufenden Periodengewinne. Auch wenn zunächst alle Marktteilnehmer Profite erzielen und über einen bestimmten Zeitraum hinweg wachsen, kann es in einem fortgeschrittenen Stadium zu Marktaustritten kommen. Grund dafür ist die Reduktion der Produktionskosten durch Lerneffekte und Externalitäten. Wir zeigen, welche notwendige Bedingung an eigene und industriespezifische Lerneffekte erfüllt sein muß, damit es zu Marktaustritten kommen kann. Ist diese Bedingung erfüllt, sind Marktaustritte um so wahrscheinlicher, je größer das Potential zur Realisierung von Lerneffekten, je kleiner der Markt, je effektiver eigenes Lernen und je geringer der externe Effekt ist. Auch in Abwesenheit von strategischem Lernen und markteintrittsverhindernder Preissetzung können Lerneffekte bedeutende Marktbarrieren begründen.

The effect of public information on competition and R&D investment

Using a simple method we show that, in contrast to the case of Bertrand and Cournot competition, better public information about demand reduces the profits of firms playing a R&D cost reduction game. Welfare increases with the precision of public information in the Cournot and cost reduction games, but not in the Bertrand game. We conclude that the provision of public information about demand in the distant future is useful and necessary in order to promote investment in R&D. Information about demand in the short term, however, should not be released. -- Mit einer einfachen Methode zeigen wir, daß im Gegensatz zum Bertrand und Cournot Wettbewerb, genauere öffentlich zugängliche Informationen über zukünftige Nachfrage die Gewinne von Firmen reduziert, die Forschungsinvestitionen zur Kostensenkung beabsichtigen. Die Wohlfahrt wird im Falle des Cournot und Forschungswettbewerbs durch bessere öffentliche Informationen erhöht, aber bei Bertrandwettbewerb verkleinert. Wir leiten daraus ab, daß die öffentliche Bereitstellung von Informationen über die zukünftige Nachfrage nützlich und notwendig ist, wohingegen Informationen die aktuelle Nachfrage betreffen nicht veröffentlicht werden sollten.

Collusion with private and aggregate information

"Der Beitrag untersucht drei linear asymmetrische Oligopol-Modelle mit (i) einem repräsentativen Verbraucher, (ii) horizontaler Differenzierung und (iii) vertikaler Differenzierung. Es wird gezeigt, daß Firmen in der Lage sind, den Gesamtprofit allein auf der Grundlage privater und gemeinschaftlicher Information zu maximieren. Sie können zur 'richtigen' Absprache des Preises gelangen, ohne die Nachfrage- oder Gewinn-Funktion zu kennen. Die Absprache stellt einen natürlichen Gleichgewichtspunkt dar, ungeachtet asymmetrischer Verhältnisse. Die Absprache kann anreizkompatibel sein, auch wenn individuelle Aktionen (Preise) nicht beobachtet werden." (Autorenreferat)"This paper considers three linear asymmetric oligopoly models with (1) a representative consumer, (2) horizontal differentiation and (3) vertical differentiation. We show that firms could maximize the joint-profit only based on private and aggregate information. They can choose the 'correct' colluding prices without knowing the demand or profit function. The collusive outcome is a natural focal point despite firms are asymmetric. Collusion can be incentive compatible even though individual actions (prices) are not observed." (author's abstract

Comparing Cournot and Bertrand equilibria revisited

This paper compares Cournot and Bertrand equilibria with mixed products, linear demand and cost functions. It is found that a firm's price (output) need not be higher (lower) in Cournot equilibrium. However, given any number of firms and a mixture of complement and substitute products, every firm's price margin/output ratio is always higher in Cournot equilibrium, and the weighted squared outputs (price margins) are higher (lower) in Bertrand equilibrium. When price (quantity) competition is a supermodular game, consumer surplus (social welfare) is higher in price competition. Nevertheless, price competition results in more market concentration measured by Herfindahl index. -- In diesem Beitrag werden Cournot- und Bertrand-Gleichgewichte für den Fall des Produktemix, linearer Nachfrage- und Kostenfunktionen verglichen. Als Ergebnis kann festgestellt werden, daß der Preis (Output) eines Unternehmens im Cournot-Gleichgewicht nicht höher (niedriger) sein muß. Angenommen, es gibt eine beliebige Zahl von Unternehmen und ein Produktemix von Komplementär- und Substitutionsgütern, dann ist der Quotient aus Preisspanne/Output immer höher im Cournot-Gleichgewicht und die gewichteten Quadrate der Outputs (Preisspannen) sind höher (niedriger) im Bertrand- Gleichgewicht. Wenn Preis-(Mengen)-Wettbewerb als supermodulares Spiel betrachtet wird, dann ist der Konsumentenüberschuß (soziale Wohlfahrt) im Falle des Preiswettbewerbs höher. Trotzdem führt Preiswettbewerb zur höherer Marktkonzentration, gemessen am Herfindahl-Index.

Detection of Oxidation Products of 5-Methyl-2′-Deoxycytidine in Arabidopsis DNA

Epigenetic regulations play important roles in plant development and adaptation to environmental stress. Recent studies from mammalian systems have demonstrated the involvement of ten-eleven translocation (Tet) family of dioxygenases in the generation of a series of oxidized derivatives of 5-methylcytosine (5-mC) in mammalian DNA. In addition, these oxidized 5-mC nucleobases have important roles in epigenetic remodeling and aberrant levels of 5-hydroxymethyl-29-deoxycytidine (5-HmdC) were found to be associated with different types of human cancers. However, there is a lack of evidence supporting the presence of these modified bases in plant DNA. Here we reported the use of a reversed-phase HPLC coupled with tandem mass spectrometry method and stable isotope-labeled standards for assessing the levels of the oxidized 5-mC nucleosides along with two other oxidatively induced DNA modifications in genomic DNA of Arabidopsis. These included 5- HmdC, 5-formyl-29-deoxycytidine (5-FodC), 5-carboxyl-29-deoxycytidine (5-CadC), 5-hydroxymethyl-29-deoxyuridine (5- HmdU), and the (59S) diastereomer of 8,59-cyclo-29-deoxyguanosine (S-cdG). We found that, in Arabidopsis DNA, the levels of 5-HmdC, 5-FodC, and 5-CadC are approximately 0.8 modifications per 106 nucleosides, with the frequency of 5-HmdC (per 5-mdC) being comparable to that of 5-HmdU (per thymidine). The relatively low levels of the 5-mdC oxidation products suggest that they arise likely from reactive oxygen species present in cells, which is in line with the lack of homologous Tetfamily dioxygenase enzymes in Arabidopsis

An integrated omics analysis reveals molecular mechanisms that are associated with differences in seed oil content between Glycine max and Brassica napus

Abstract Background: Rapeseed (Brassica napus L.) and soybean (Glycine max L.) seeds are rich in both protein and oil, which are major sources of biofuels and nutrition. Although the difference in seed oil content between soybean (~ 20%) and rapeseed (~ 40%) exists, little is known about its underlying molecular mechanism. Results: An integrated omics analysis was performed in soybean, rapeseed, Arabidopsis (Arabidopsis thaliana L. Heynh), and sesame (Sesamum indicum L.), based on Arabidopsis acyl-lipid metabolism- and carbon metabolism-related genes. As a result, candidate genes and their transcription factors and microRNAs, along with phylogenetic analysis and co-expression network analysis of the PEPC gene family, were found to be largely associated with the difference between the two species. First, three soybean genes (Glyma.13G148600, Glyma.13G207900 and Glyma.12G122900) co-expressed with GmPEPC1 are specifically enriched during seed storage protein accumulation stages, while the expression of BnPEPC1 is putatively inhibited by bna-miR169, and two genes BnSTKA and BnCKII are co-expressed with BnPEPC1 and are specifically associated with plant circadian rhythm, which are related to seed oil biosynthesis. Then, in de novo fatty acid synthesis there are rapeseed-specific genes encoding subunits β-CT (BnaC05g37990D) and BCCP1 (BnaA03g06000D) of heterogeneous ACCase, which could interfere with synthesis rate, and β-CT is positively regulated by four transcription factors (BnaA01g37250D, BnaA02g26190D, BnaC01g01040D and BnaC07g21470D). In triglyceride synthesis, GmLPAAT2 is putatively inhibited by three miRNAs (gma-miR171, gma-miR1516 and gma-miR5775). Finally, in rapeseed there was evidence for the expansion of gene families, CALO, OBO and STERO, related to lipid storage, and the contraction of gene families, LOX, LAH and HSI2, related to oil degradation. Conclusions: The molecular mechanisms associated with differences in seed oil content provide the basis for future breeding efforts to improve seed oil content

An integrated bioinformatics analysis reveals divergent evolutionary pattern of oil biosynthesis in high- and low-oil plants

Seed oils provide a renewable source of food, biofuel and industrial raw materials that is important for humans. Although many genes and pathways for acyl-lipid metabolism have been identified, little is known about whether there is a specific mechanism for high-oil content in high-oil plants. Based on the distinct differences in seed oil content between four high-oil dicots (20~50%) and three low-oil grasses (<3%), comparative genome, transcriptome and differential expression analyses were used to investigate this mechanism. Among 4,051 dicot-specific soybean genes identified from 252,443 genes in the seven species, 54 genes were shown to directly participate in acyl-lipid metabolism, and 93 genes were found to be associated with acyl-lipid metabolism. Among the 93 dicot-specific genes, 42 and 27 genes, including CBM20-like SBDs and GPT2, participate in carbohydrate degradation and transport, respectively. 40 genes highly up-regulated during seed oil rapid accumulation period are mainly involved in initial fatty acid synthesis, triacylglyceride assembly and oil-body formation, for example, ACCase, PP, DGAT1, PDAT1, OLEs and STEROs, which were also found to be differentially expressed between high- and low-oil soybean accessions. Phylogenetic analysis revealed distinct differences of oleosin in patterns of gene duplication and loss between high-oil dicots and low-oil grasses. In addition, seed-specific GmGRF5, ABI5 and GmTZF4 were predicted to be candidate regulators in seed oil accumulation. This study facilitates future research on lipid biosynthesis and potential genetic improvement of seed oil content