We propose a model of monopolistic competition with additive preferences and variable marginal costs. Using the concept of "relative love for variety," we provide a full characterization of the ...free-entry equilibrium. When the relative love for variety increases with individual consumption, the market generates pro-competitive effects. When it decreases, the market mimics anti-competitive behavior. The constant elasticity of substitution is the only case in which all competitive effects are washed out. We also show that our results hold true when the economy involves several sectors, firms are heterogeneous, and preferences are given by the quadratic utility and the translog.
Competition among the big and the small Shimomura, Ken-Ichi; Thisse, Jacques-François
The Rand journal of economics,
06/2012, Letnik:
43, Številka:
2
Journal Article
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Many industries are made up of a few big firms, which are able to manipulate the market outcome, and of a host of small businesses, each of which has a negligible impact on the market We provide a ...general equilibrium framework that encapsulates both market structures. Due to the higher toughness of competition, the entry of big firms leads them to sell more through a market expansion effect generated by the shrinking of the monopolistically competitive fringe. Furthermore, social welfare increases with the number of big firms because the procompetitive effect associated with entry dominates the resulting decrease in product diversity.
We study how technological progress in manufacturing and migration costs interact to shape the space economy. Rising labor productivity in the manufacturing sector fosters the agglomeration of ...activities, whereas falling transport costs associated with technological and organizational innovations foster their dispersion. Since these two forces have been at work for a long time, the final outcome must depend on how drops in the costs of producing and trading goods interact with the various costs borne by migrants. Various extensions show the robustness of these conclusions.
The purpose of this article is twofold. First, we present an alternative model of agglomeration and trade that displays the main features of the recent economic geography literature while allowing ...for the derivation of analytical results by means of simple algebra. Second, we show how this framework can be used to permit (i) a welfare analysis of the agglomeration process, (ii) a full-fledged forward-looking analysis of the role of history and expectations in the emergence of economic clusters, and (iii) a simple analysis of the impact of urban costs on the spatial distribution of economic activities.
We analyze the strategic interaction between mitigation (public good) and adaptation (private good) strategies in a climate agreement. We show the fear that adaptation will reduce the incentives to ...mitigate carbon emissions may be unwarranted. Adaptation can lead to larger self-enforcing agreements, associated with higher global mitigation levels and welfare if it causes mitigation levels between different countries to be no longer strategic substitutes but complements. We argue that our results extend to many public goods. The well-known problem of “easy riding” may turn into “easy matching” if the marginal utility of public good consumption is strongly influenced by private consumption.
•Adaptation does not necessarily reduce the incentives to mitigate carbon emissions.•With adaptation, reaction functions in mitigation space may be upward sloping.•Adaptation can lead to larger self-enforcing agreements.•Adaptation can lead to higher global mitigation levels and welfare.
Pseudogenes are mutated copies of protein-coding genes that cannot be translated into proteins, but a small subset of pseudogenes has been detected at the protein level. Although ubiquitin ...pseudogenes represent one of the most abundant pseudogene families in many organisms, little is known about their expression and signaling potential. By re-analyzing public RNA-sequencing and proteomics datasets, we here provide evidence for the expression of several ubiquitin pseudogenes including UBB pseudogene 4 (UBBP4), which encodes Ub
(Q2K, K33E, Q49K, N60S). The functional consequences of Ub
conjugation appear to differ from canonical ubiquitylation. Quantitative proteomics shows that Ub
modifies specific proteins including lamins. Knockout of UBBP4 results in slower cell division, and accumulation of lamin A within the nucleolus. Our work suggests that a subset of proteins reported as ubiquitin targets may instead be modified by ubiquitin variants that are the products of wrongly annotated pseudogenes and induce different functional effects.
Large and productive metropolitan areas play a growing role in the working of developed and emerging economies alike. This paper surveys the recent contributions of urban economics, highlighting the ...role of external increasing returns—called agglomeration economies in the context of a city, which are key in the development and functioning of large, prosperous cities. One critical feature of these mechanisms is their cumulative nature: once set in motion, they feed themselves. The various costs associated with city size put a brake on such mechanisms. In many countries, the unevenness of the distribution of skilled labor across cities is both the cause and the consequence of particular agglomeration economies. Human capital is beneficial to the cities, which attract skills and talents. However, cities’ spatial concentration exacerbates regional disparities at the risk of generating strong political and social tensions within nations.
Summary
Compressed bitmap indexes are used in systems such as Git or Oracle to accelerate queries. They represent sets and often support operations such as unions, intersections, differences, and ...symmetric differences. Several important systems such as Elasticsearch, Apache Spark, Netflix's Atlas, LinkedIn's Pivot, Metamarkets' Druid, Pilosa, Apache Hive, Apache Tez, Microsoft Visual Studio Team Services, and Apache Kylin rely on a specific type of compressed bitmap index called Roaring. We present an optimized software library written in C implementing Roaring bitmaps: CRoaring. It benefits from several algorithms designed for the single‐instruction–multiple‐data instructions available on commodity processors. In particular, we present vectorized algorithms to compute the intersection, union, difference, and symmetric difference between arrays. We benchmark the library against a wide range of competitive alternatives, identifying weaknesses and strengths in our software. Our work is available under a liberal open‐source license.
Summary
RyhB is a small RNA (sRNA) that downregulates about 20 genes involved in iron metabolism. It is expressed under low iron conditions and pairs with specific mRNAs to trigger their rapid ...degradation by the RNA degradosome. In contrast to this, another study has suggested that RyhB also activates several genes by increasing their mRNA level. Among these activated genes is shiA, which encodes a permease of shikimate, an aromatic compound participating in the biosynthesis of siderophores. Here, we demonstrate in vivo and in vitro that RyhB directly pairs at the 5′‐untranslated region (5′‐UTR) of the shiA mRNA to disrupt an intrinsic inhibitory structure that sequesters the ribosome‐binding site (Shine‐Dalgarno) and the first translation codon. This is the first demonstration of direct gene activation by RyhB, which has been exclusively described in degradation of mRNAs. Our physiological results indicate that the transported compound of the ShiA permease, shikimate, is important under conditions of RyhB expression, that is, iron starvation. This is demonstrated by growth assays in which shikimate or the siderophore enterochelin correct the growth defect observed for a ryhB mutant in iron‐limited media.
The European Union (EU) Green Deal and its Farm to Fork Strategy are intended to promote sustainable food systems to achieve EU climate-neutrality by 2050. The Farm to Fork action plan also foresees ...the introduction of a harmonized mandatory front-of-pack nutrition labelling scheme in 2023. The EU countries have yet to reach agreement on the nutrition labelling scheme, which will also have environmental impacts. This article raises the question of whether at the European level, countries should seek agreements on both climate mitigation and nutrition policies (full agreement as in the case of the Green Deal) or should negotiate separate climate and nutrition policy agreements (as for the nutritional labelling). To address this question, this paper develops a game-theoretic model with multiple countries where each country implements a climate policy and a nutrition policy. We compare the consequences in terms of total emissions, the level of the nutrition policy and the welfare under different institutional arrangements of a non-cooperative equilibrium, full agreement, and three alternative agreements. Our results show in particular that full agreement always leads to the lowest total emissions at the expense of the level of nutrition policy in some cases. In an extension of our analysis, we show that agreements that include cooperation over nutrition policies do not necessarily imply formation of a larger coalition of signatory countries, even if a nutrition policy has positive or negative impacts on emissions.
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