Congestion pricing, infrastructure investment and redistribution

We study congestion pricing by a government that has redistributive concerns, in the presence of optimal income taxation. Individuals differ in (unobservable) earning ability and consumption technology for commodities using a congestible network (e.g. roads, Internet). We find, assuming separable preferences, that when efficiency of consumption technology is either invariant or postively correlated with earning ability, low ability individuals should face higher marginal congestion charges than high ability ones. Moreover, reducing congestion (by raising charges or expanding network capacity) enables government to increase redistribution. We also find that means tested congestion pricing may be necessary to implement the second-best allocation.congestion pricing; income taxation; redistribution; infrastructure investment

Influence of different iron availability on phosphoenolpiruvate carboxilase and malate dehydrogenase in roots of maize (Zea Mays L.) plants grown under iron deficiency

The effect of the different nitrate availability on some enzymatic activities has been evaluated in iron deficient and iron sufficient maize plants (Zea mays L.). In order to evaluate if the induction of sensitive to pH enzymatic activities is affected by the variation of the apoplast reaction due to the different nitrate availability, two experimental tests were done on maize plants grown in nutrient solution with different NO3- availability and with Fe-sufficiency (+Fe) (added with 80 uM Fe(III)-EDTA) and Fe-deficiency (-Fe) (added with 0.1 uM Fe(III)-EDTA).
As regards 0.4 mM NO3- (NS2), independently of iron availability, phosphoenolpiruvate carboxilase and malate dehydrogenase inductions are higher than those recorded for the experiment with 4.0 mM NO3-. The two activities, for the reaction determined in citosol by NO3- uptake, show different responses according to Fe availability. In NS1 the higher nitrate uptake and the contemporaneous H+ incoming cause in (+Fe) plants a decrease of PEP-carboxilase activation and, during the first 24 hours, of malate dehydrogenase. The shifting of the peak of maximum activity shows that iron deficiency conditions, interfering with e- transport, determinate a slowing down of the enzyme induction, independently of nitrate availability. In NS2, PEPcase is higher under Fe-deficiency and malate dehydrogenase is higher under Fe-sufficiency, both during the first 24 hours.
The different nitrate availability causes a different use of the acid content. In fact, in NS1 citric content, precursor of molecules for the production of phytosiderophores, increased in (-Fe) theses. On the contrary, low nitrate availabilities determined a decrease in acid contents, mostly in (-Fe) theses. This result justifies the higher energy demand to activate membrane carriers under stress conditions for the reduced nitrate availability.
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Creative workers and regional development. Towards a classification of spatial effects

Using data from the Labour Force Surveys in the 2001-2008 period, this paper analyses the evolution in the distribution of “creative professions†as a share of regional workforces (at NUTS2 level), and correlates it with the evolution of p.c. GDP, in different time periods, to test the hypothesis of causal relationship between the two variables, in either direction. It then proposes a regional classification based on the spatial clustering of these effects, which highlights the existence of “national effects†and the relevance of geographical specificities.

Urban fashion policies: lessons from the Barcelona catwalks

Since at least a decade, Barcelona is on the world map of fashion: Antonio Mirò, Mango, Desigual, Agatha Ruiz de la Prada are famous Barcelona-based stylists teaming up with other large Spanish fashion firms, like Zara, and commercial outlets, like El Corte Ingles, to attract a large interest on local fashion and fashion-based events. Thus, Barcelona has become a straightforward “shopping destination” for millions of international visitors, developing a shopping-related image, various specialised “fashion clusters” for different market targets, and a number of fashion-related events attracting both professionals and a dedicated general audience, like the 080 Barcelona and Bread & Butter. Barcelona’s liberal and leisure-related image can be easily associated with fashion, so if the national capital Madrid retains its role of business capital of the country even in relation to fashion, Barcelona could be considered the emergent “catwalk” of the Mediterranean, challenging other fashion capitals of Europe like Milan and Paris. The article analyses the urban strategy to foster the fashion industry in Barcelona through a redefinition of the “soft” factors establishing the substance of a fashion capital: image, place qualities, events, connectedness and social embeddedness. Tourism, unsurprisingly, is an important component of such strategy. The growth of Barcelona to the stardom of international leisure and cultural tourism is mostly about the “liminal” nature and the symbolically-charged activities of visitors that can be easily extended to fashion and fashion buying behaviour. Through a number of interviews and the analysis of strategy documents and reports, the authors unravel this relationship and assess the effectiveness of this strategy face to other factors playing against a more enduring rooting of fashion industries in the city, like the volatility of the sector, the insufficient international connectedness of the city and its business orientation, and the reorientation of the tourist supply towards low-cost visitors segments.