7,642 research outputs found
Matching Long and Short Distances in Large-Nc QCD
It is shown, with the example of the experimentally known Adler function,
that there is no matching in the intermediate region between the two asymptotic
regimes described by perturbative QCD (for the very short-distances) and by
chiral perturbation theory (for the very long-distances). We then propose to
consider an approximation of large-Nc QCD which consists in restricting the
hadronic spectrum in the channels with J^P quantum numbers 0^-, 1^-, 0^+ and
1^+ to the lightest state and treating the rest of the narrow states as a
perturbative QCD continuum; the onset of this continuum being fixed by
consistency constraints from the operator product expansion. We show how to
construct the low-energy effective Lagrangian which describes this
approximation. The number of free parameters in the resulting effective
Lagrangian can be reduced, in the chiral limit where the light quark masses are
set to zero, to just one mass scale and one dimensionless constant to all
orders in chiral perturbation theory. A comparison of the corresponding
predictions, to O(p^4) in the chiral expansion, with the phenomenologically
known couplings is also made.Comment: 35 pages, 9 figures, LaTeX. Added a couple of reference
Poverty effects of higher food prices : a global perspective
The spike in food prices between 2005 and the first half of 2008 has highlighted the vulnerabilities of poor consumers to higher prices of agricultural goods and generated calls for massive policy action. This paper provides a formal assessment of the direct and indirect impacts of higher prices on global poverty using a representative sample of 63 to 93 percent of the population of the developing world. To assess the direct effects, the paper uses domestic food consumer price data between January 2005 and December 2007--when the relative price of food rose by an average of 5.6 percent --to find that the implied increase in the extreme poverty headcount at the global level is 1.7 percentage points, with significant regional variation. To take the second-order effects into account, the paper links household survey data with a global general equilibrium model, finding that a 5.5 percent increase in agricultural prices (due to rising demand for first-generation biofuels) could raise global poverty in 2010 by 0.6 percentage points at the extreme poverty line and 0.9 percentage points at the moderate poverty line. Poverty increases at the regional level vary substantially, with nearly all of the increase in extreme poverty occurring in South Asia and Sub-Saharan Africa.Rural Poverty Reduction,Food&Beverage Industry,Poverty Lines,Emerging Markets
Economic performance under NAFTA : a firm-level analysis of the trade-productivity linkages
Did the North American Free Trade Agreement make Mexican firms more productive? If so, through which channels? This paper addresses these questions by deploying an innovative microeconometric approach that disentangles the various channels through which integration with the global markets (via international trade) can affect firm-level productivity. The results show that the North American Free Trade Agreement stimulated the productivity of Mexican plants via: (1) an increase in import competition and (2) a positive effect on access to imported intermediate inputs. However, the impact of trade reforms was not identical for all integrated firms, with fully integrated firms (i.e. firms simultaneously exporting and importing) benefiting more than other integrated firms. Contrary to previous results, once self-selection problems are solved, the analysis finds a rather weak relationship between exports and productivity growth.Economic Theory&Research,Free Trade,Labor Policies,Knowledge for Development,Microfinance
Anomalous Thresholds and the Isgur-Wise Function
The original de Rafael-Taron bound on the slope of the Isgur-Wise function at
zero recoil is known to be violated in QCD by singularities appearing in an
unphysical region. To be consistent, quark models must have corresponding
singularity structures. In an existing relativistic quark-loop model, the
meson-quark-antiquark vertex is such that the required singularity is an
anomalous threshold. We also discuss the implications of another anomalous
threshold, whose location is determined by quark masses alone.Comment: 8 pages, LaTeX, 4 LaTeX figures in separate uufile, UTPT-94-0
Can Maquila Booms Reduce Poverty? Evidence from Honduras
This paper identifies and estimates the strength of the reduction in poverty linked to improved opportunities for women in the expanding maquila sector. A simulation exercise shows that, at a given point in time, poverty in Honduras would have been 1.5 percentage points higher had the maquila sector not existed. Of this increase in poverty, 0.35 percentage points is attributable to the wage premium paid to maquila workers, 0.1 percentage points to the wage premium received by women in the maquila sector, and 1 percentage point to employment creation. Given that female maquila workers represent only 1.1 percent of the active population in Honduras, this contribution to poverty reduction is significant.Trade liberalization; maquila; poverty; gender wage gap; Honduras
Distributional effects of the Panama Canal expansion
This paper uses a dynamic macro-micro framework to evaluate the potential distributional effects of the expansion of the Panama Canal. The results show that large macroeconomic effects are only likely during the operations phase (2014 and onward), and income gains are likely to be concentrated at the top of the income distribution. The additional foreign exchange inflows during the construction and operations phases result in the loss of competitiveness of non-Canal sectors (Dutch disease) and in higher domestic prices, which hurt the poorest consumers. In addition, the construction and operation activities increase demand for more educated non-farm formal workers. Although these changes encourage additional labor movement out of agriculture and from the informal to the formal sector, much of the impact is manifested in growing wage disparities and widening income inequality. Using the additional revenues of the Canal expansion in a targeted cash transfer program such as"Red de Oportunidades", the Government of Panama could offset the adverse distributional effects and eradicate extreme poverty.Economic Theory&Research,Labor Policies,Markets and Market Access,Labor Markets,Emerging Markets
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