Trade Liberalization and Trade Tax Revenues in African Countries

We empirically investigate the e®ect of trade liberalization on trade tax revenues applying panel-data methods to a large sample of African countries from the period 1970-2000. The goal of this paper is to determine whether controlling for macroeconomic features of African economies and taking into account the existence of political constraints that might either support or weaken the power of the trade reform, a change in trade policy has a positive or negative e®ect on trade tax revenues. We ¯nd that there exists a large trade o® between a greater degree of openness to international trade and the revenue collected from import and export taxation. We document the existence of a La®er ef- fect between trade openness and trade tax revenues and stress the impor- tance of exchange rate policies along with the stability of the macroeco- nomic environment in determining trade reform outcomes. Interestingly, we also provide evidence of the relevance of government credibility in explaining trade tax revenues.

Configuration spaces are not homotopy invariant

We present a counterexample to the conjecture on the homotopy invariance of configuration spaces. More precisely, we consider the lens spaces $L_{7,1}$ and $L_{7,2}$, and prove that their configuration spaces are not homotopy equivalent by showing that their universal coverings have different Massey products.Comment: 6 page

Fractal geometry of nature (bone) may inspire medical devices shape

Medical devices, as orthopaedics prostheses and dental implants, have been designed over years on the strength of mechanical, clinical and biological indications. This sequence is the commonly accepted cognitive and research process: adapting the device to the surrounding environment (host tissue). Inverting this traditional logical approach, we started from bone microarchitecture analysis. Here we show that a unique geometric rule seems to underlie different morphologic and functional aspects of human jaw bone tissue: fractal properties of white trabeculae in low quality bone are similar to fractal properties of black spaces in high quality bone and vice versa. These data inspired the fractal bone quality classification and they were the starting point for reverse engineering to design specific dental implants threads. We introduce a new philosophy: bone decoding and with these data devices encoding. In the future, the method will be implemented for the analysis of other human or animal tissues in order to project medical devices and biomaterials with a microarchitecture driven by nature

Associative algebras, punctured disks and the quantization of Poisson manifolds

The aim of the note is to provide an introduction to the algebraic, geometric and quantum field theoretic ideas that lie behind the Kontsevich-Cattaneo-Felder formula for the quantization of Poisson structures. We show how the quantization formula itself naturally arises when one imposes the following two requirements to a Feynman integral: on the one side it has to reproduce the given Poisson structure as the first order term of its perturbative expansion; on the other side its three-point functions should describe an associative algebra. It is further shown how the Magri-Koszul brackets on 1-forms naturally fits into the theory of the Poisson sigma-model.Comment: LaTeX, 8 pages, uses XY-pic. Few typos corrected. Final versio

Inequality, Political Systems and Public Spending

Political regimes and institutions di®er across countries. Such char- acteristics in°uence public spending within each country. The aim of this paper is to check for the existence of a link between political institu- tions, income inequality and public spending. We develop an empirical investigation, based on panel data analysis, on the determinants of pub- lic spending focusing on political, economic, demographic and social variables in large sample of developed and developing countries from 1970 to 2005. In particular, we focus on the e®ects of electoral rules on government consumption ¯nding that in countries with proportional electoral rule an increase in the heterogeneity of the government in- creases government consumption, while in countries with majoriratian electoral rule, a shift from presidential to parliamentary system leads to an increase in government consumption. We ¯nd that the link between income distribution, measured by the Gini index, and public spending depends upon institutional characteristics. Moreover, we ¯nd empiri- cal support for the argument that government spending is a policy tool used by governments to insurance the domestic economy from external shocks stemming from international trade.

Industrial Policy and Artisan Firms in Italy 1945-1971

This paper shows that from the end of WW2 to the establishment of the regional governments in the early 1970s the Italian state carried out an artisanship policy (that is, for the smallest firms) of an extent that was unparalleled in Europe. This policy was based on the provision, on the one hand, of lower tax and employers' contributions and welfare benefits at reduced premiums and, on the other hand, of 'substitutive factors': soft loans, services and promotional initiatives by state agencies. Such an artisan policy played a twofold role: partly 'defensive', protecting a segment of marginal firms, and partly 'proactive', prompting modernisation and innovation of more promising firms. The latter were clustered especially in the industrial district of the centre and north-easte of the country, whose development turned out to be boosted to a significant extent by state intervention.Italy; Industrial districts; Artisanship policy

On the Hochschild-Kostant-Rosenberg map for graded manifolds

We show that the Hochschild-Kostant-Rosenberg map from the space of multivector fields on a graded manifold N (endowed with a Berezinian volume) to the cohomology of the algebra of multidifferential operators on N (as a subalgebra of the Hochschild complex of the algebra of smooth functions on N) is an isomorphism of Batalin-Vilkovisky algebras. These results generalize to differential graded manifolds.Comment: 15 pages. Problematic Lemma 5.5 of v1 removed and Theorem 5.3b corrected accordingly. Exposition reorganized. To appear in IMR

Industrial Policy and Artisan Firms in Italy, 1945-1981

This paper shows that after the Second World War the Italian state carried out an artisanship policy (that is, for the smallest firms) of an extent that was unparalleled in Europe. This policy was based on the provision, on the one hand, of lower tax and employers' contributions and welfare benefits at reduced premiums and, on the other hand, of 'substitutive factors': soft loans, services and promotional initiatives by state agencies. Such an artisan policy played a twofold role: partly 'defensive', protecting a segment of marginal firms, and partly 'proactive', prompting modernisation and innovation of more promising firms. The latter were clustered especially in the industrial district of the centre and north-easte of the country, whose development turned out to be boosted to a significant extent by state intervention.Italy; Industrial districts; Artisan firms; Indsutrial Policy