1,726 research outputs found
European integration, FDI and the internal geography of trade : evidence from Western European border regions
In this paper we use a gravity model to study the trade performance of French and Spanish
border regions relatively to non-border regions, over the past two decades. We find that,
controlling for their size, proximity and location characteristics, border regions trade on
average between 62% and 193% more with their neighbouring country than other regions,
and twice as much if they are endowed with good cross border transport infrastructures.
Despite European integration, however, this trade outperformance has fallen for the most
peripheral regions within the EU. We show that this trend was linked in part to a shift in the propensity of foreign investors to move their affiliates from the regions near their home market to the regions bordering the EU core.- En aquest article analitzem el rendiment comercial relatiu de les regions frontereres a
França i Espanya, mitjançant un model de gravetat. Els nostres resultats mostren que,
controlant per la dimensió, la proximitat i les característiques de les localitzacions, les
regions frontereres comercien en mitjana entre un 62% i un 193% més que les altres regions amb els estats veïns, i més del doble si estan dotades amb bones infrastructures transfrontereres de transport. Ara bé, malgrat el procés d'integració europeu, aquest rendiment superior ha disminuït per les regions més perifèriques de la UE. Mostrem que aquesta tendència està lligada en part a un canvi en la propensió dels inversors estrangers a localitzar les seves filials des de les regions més properes al seu mercat d'origen cap a les regions properes al centre de la UE
How to prevent type-flaw attacks on security protocols under algebraic properties
Type-flaw attacks upon security protocols wherein agents are led to
misinterpret message types have been reported frequently in the literature.
Preventing them is crucial for protocol security and verification. Heather et
al. proved that tagging every message field with it's type prevents all
type-flaw attacks under a free message algebra and perfect encryption system.
In this paper, we prove that type-flaw attacks can be prevented with the same
technique even under the ACUN algebraic properties of XOR which is commonly
used in "real-world" protocols such as SSL 3.0. Our proof method is general and
can be easily extended to other monoidal operators that possess properties such
as Inverse and Idempotence as well. We also discuss how tagging could be used
to prevent type-flaw attacks under other properties such as associativity of
pairing, commutative encryption, prefix property and homomorphic encryption.Comment: 16 pages, Appeared in proceedings of Security with Rewriting
Techniques (SecRet09), Affiliated to CSF Symposium 2009, Port Jefferson, NY
Bridging over p-wave pi-production and weak processes in few-nucleon systems with chiral perturbation theory
I study an aspect of chiral perturbation theory (\chi PT) which enables one
to ``bridge'' different reactions. That is, an operator fixed in one of the
reactions can then be used to predict the other. For this purpose, I calculate
the partial wave amplitude for the p-wave pion production (pp\to pn\pi^+) using
the pion production operator from the lowest and the next nonvanishing orders.
The operator includes a contact operator whose coupling has been fixed using a
matrix element of a low-energy weak process (pp\to de^+\nu_e). I find that this
operator does not reproduce the partial wave amplitude extracted from
experimental data, showing that the bridging over the reactions with
significantly different kinematics is not necessarily successful. I study the
dependence of the amplitude on the various inputs such as the NN potential, the
\pi N\Delta coupling, and the cutoff. I argue the importance of a higher order
calculation. In order to gain an insight into a higher order calculation, I add
a higher order counter term to the operator used above, and fit the couplings
to both the low-energy weak process and the pion production. The energy
dependence of the partial wave amplitude for the pion production is described
by the operator consistently with the data. However, I find a result which
tells us to be careful about the convergence of the chiral expansion for the
pp\to pn\pi^+ reaction.Comment: 30 pages, 13 figures, figures changed, compacted tex
European integration, FDI and the geography of French trade
This paper uses an augmented gravity model to investigate whether the 1978-2000 process of European integration has changed the geography of trade within France, with a particular focus on the trends experienced by border regions. We support the conclusion that, once controlled for bilateral distance, origin- and destination-specific characteristics, French border regions trade on average 72% more with nearby countries than predicted by the gravity norm. They perform even better (114%) if they have good cross-border transport connections to the neighboring country. However, this outperformance eroded drastically for the French border regions located at the periphery of Europe throughout integration. We show that this trend is partly due to a decreasing propensity of foreign affliates to trade with their home country. This trade reorientation is less pronounced for the Belgian-Luxembourgian and German firms located in the regions which have better access to the EU core.trade ; gravity ; border regions ; European integration ; foreign direct investment
Concentration, agglomeration and the size of plants
This paper investigates whether the geographic distribution of manufacturing activities depends on the size of plants. Using Italian data we find, as in Kim (1995) and Holmes and Stevens (2002, 2004), that large plants are more concentrated than small plants. However, considering distance-based patterns via spatial auto-correlation, we find that small establishments actually exhibit a greater tendency to be located in adjacent areas. These apparently contradictory findings raise a measurement issue regarding co-location externalities, and suggest that large plants are more likely to cluster within narrow geographical units (concentration), while small establishments would rather co-locate within wider distance-based clusters (agglomeration). This picture is consistent with different size plants engaging in different transport-intensive activities.concentration ; spatial auto-correlation ; plant size
European Integration, FDI and the Internal Geography of Trade: Evidence from Western European Border Regions
In this paper we use a gravity model to study the trade performance of French and Spanish border regions relatively to non-border regions, over the past two decades. We find that, controlling for their size, proximity and location characteristics, border regions trade on average between 62% and 193% more with their neighbouring country than other regions, and twice as much if they are endowed with good cross border transport infrastructures. Despite European integration, however, this trade outperformance has fallen for the most peripheral regions within the EU. We show that this trend was linked in part to a shift in the propensity of foreign investors to move their affiliates from the regions near their home market to the regions bordering the EU core.direct investment, border regions, gravity, trade, european integration, foreign
Physical Zero-Knowledge Proofs for Akari, Takuzu, Kakuro and KenKen
Akari, Takuzu, Kakuro and KenKen are logic games similar to Sudoku. In Akari,
a labyrinth on a grid has to be lit by placing lanterns, respecting various
constraints. In Takuzu a grid has to be filled with 0's and 1's, while
respecting certain constraints. In Kakuro a grid has to be filled with numbers
such that the sums per row and column match given values; similarly in KenKen a
grid has to be filled with numbers such that in given areas the product, sum,
difference or quotient equals a given value. We give physical algorithms to
realize zero-knowledge proofs for these games which allow a player to show that
he knows a solution without revealing it. These interactive proofs can be
realized with simple office material as they only rely on cards and envelopes.
Moreover, we formalize our algorithms and prove their security.Comment: FUN with algorithms 2016, Jun 2016, La Maddalena, Ital
Dots to boxes: Do the size and shape of spatial units jeopardize economic geography estimations?
This paper evaluates, in the context of economic geography estimates, the magnitude of the distortions arising from the choice of zoning system, which is also known as the Modifiable Areal Unit Problem (MAUP). We consider three standard economic geography exercises (the analysis of spatial concentration, agglomeration economies, and trade determinants), using various French zoning systems differentiated according to the size and shape of spatial units, which are the two main determinants of the MAUP. While size matters a little, shape does so much less. Both dimensions seem to be of secondary importance compared to specification issues.MAUP ; concentration ;agglomeration ;wage equations ;gravity
DOTS TO BOXES: DO THE SIZE AND SHAPE OF SPATIAL UNITS JEOPARDIZE ECONOMIC GEOGRAPHY ESTIMATIONS?
This paper evaluates, in the context of economic geography estimates, the magnitude of the distortions arising from the choice of zoning system, which is also known as the Modifiable Areal Unit Problem (MAUP). We consider three standard economic geography exercises (the analysis of spatial concentration, agglomeration economies, and trade determinants), using various French zoning systems differentiated according to the size and shape of spatial units, which are the two main determinants of the MAUP. While size matters a little, shape does so much less. Both dimensions seem to be of secondary importance compared to specification issues.MAUP, concentration, agglomeration, wage equations, gravity
Can Business and Social Networks Explain the Border Effect Puzzle?
McCallum (1995) shows in an influential contribution that, even when controlling for the impact of bilateral distance and region size, borders sharply reduce trade volumes between countries. We use in this paper data on bilateral trade flows between 94 French regions, for 10 industries and 2 years (1978 and 1993) to study the magnitude and variations over time of trade impediments, both distance-related and (administrative) border-related. We focus on assessing the role that business and social networks can play in shaping trade patterns and explaining the border effect puzzle. Using a structural econometric approach, we show that intra-national administrative borders significantly affect trade patterns inside France. The impact is of the same order of magnitude as in Wolf (2000) for trade inside the United States. We show that more than 60\% of these (puzzling) intra-national border effects can be explained by the composition of local labour force in terms of birth place (social networks) and by inter-plants connections (business networks). In addition, controlling for these network effects reduces the impact of transport cost on trade flows by a comparable factor. Thus, business and social networks that help to reduce informational trade barriers are shown to be strong determinants of trade patterns and to explain a large part of the border puzzle.gravity, border effects, networks
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