Learning, Incomplete Contracts and Export Dynamics: Theory and Evidence from French Firms

We consider a model where exporting requires finding a local partner in each market. Contracts are incomplete and exporters must learn the reliability of their partners through experience. In the model, export behavior is state-dependent due to matching frictions, although there are no sunk costs. Better legal institutions alleviate contracting frictions especially in sectors with large contracting problems. Thus, measures of legal quality help reduce the risk that a match between an exporter and a local distributor splits, and they are all the more effective in sectors that are more exposed to hold-up problems. Moreover, the breaking risk declines with the age of the relationship, as unreliable partners are weeded out. We find strong evidence in favor of the model's predictions when testing them with a French dataset that includes information on firm-level exports by destination country.Trade Dynamics, Learning, Incomplete Contracts, State dependence, Firm-level Trade Data

Variations in tephra stratigraphy created by small-scale surface features in sub-polar landscapes

Financial support for this work was provided by NERC Doctoral Training Partnership Ph.D. studentship NE/L002558/1 to Polly I. J. Thompson.We explore the effect small-scale surface features have on influencing the morphology and grain-size distribution (GSD) of tephra layers within the Quaternary stratigraphy of sub-polar landscapes. Icelandic thúfur, small cryogenic earth mounds, are used to assess how and why the morphology and GSD of tephra layers vary over such formations. Through measurement of tephra layer thickness and GSD, Hekla 1947 and Grímsvötn 2011 tephra layers are analysed. Results indicate that such microtopographic features do indeed alter the form of tephra deposits and therefore the tephra layer that is preserved in the stratigraphy. Tephra thickness is significantly greater in hollows than on the thúfur crests. There is greater variation in tephra thickness measurements from thúfur in comparison to control measurements from a surface where thúfur are absent. Thúfur crests contain larger grain sizes than hollows, for both H1947 and G2011 tephras; however this was only statistically significant for the G2011 tephra. Such morphological patterns are thought to arise from an interplay of tephra characteristics, altered topography from the thúfur formations and earth surface processes operating at the sites. This study provides insight into the potential of tephra layer morphology and internal structures as indicators of Quaternary landforms and processes. Additionally, it provides important context for the appropriate sampling of tephra layers to infer volcanological processes, as the characteristics of preserved layers do not necessarily reflect those of the original fall-out.Publisher PDFPeer reviewe

Impact of small-scale vegetation structure on tephra layer preservation.

The factors that influence tephra layer taphonomy are poorly understood, but vegetation cover is likely to play a role in the preservation of terrestrial tephra deposits. The impact of vegetation on tephra layer preservation is important because: 1) the morphology of tephra layers could record key characteristics of past land surfaces and 2) vegetation-driven variability in tephra thickness could affect attempts to infer eruption and dispersion parameters. We investigated small- (metre-) scale interactions between vegetation and a thin (<10 cm), recent tephra layer. We conducted surveys of vegetation structure and tephra thickness at two locations which received a similar tephra deposit, but had contrasting vegetation cover (moss vs shrub). The tephra layer was thicker and less variable under shrub cover. Vegetation structure and layer thickness were correlated on the moss site but not under shrub cover, where the canopy reduced the influence of understory vegetation on layer morphology. Our results show that vegetation structure can influence tephra layer thickness on both small and medium (site) scales. These findings suggest that some tephra layers may carry a signal of past vegetation cover. They also have implications for the sampling effort required to reliably estimate the parameters of initial deposits

Restrictive Fiscal Policies in Europe: What are the Likely Effects?

In Europe, fiscal policy will be distinctly more restrictive from 2011 onwards. The fiscal consolidation efforts scheduled for 2011 represent 1.2 percentage points of GDP in the eurozone and 1.8 percentage points in the UK. Such adjustments hit short-term demand and depress activity by Keynesian effects. However, non-Keynesian mechanisms can attenuate them, not least through expectations and supply effects. The impact of fiscal consolidation is also related to the economic background: in line with the recent developments on sovereign bond markets, fiscal variables are found to have a significant impact on interest rate spreads on euro area public bonds. According to our main result, when debt exceeds 100 percentage points of GDP, the marginal effect on the spread of one additional point of debt would be about 7 to 8 basis points. Accordingly, fiscal consolidation is likely to weigh down on euro area sovereign risk premiums. In this light, the NiGEM international macroeconomic model is used to assess the GDP impact of European fiscal consolidation plans. Overall, euro area's GDP in 2011 is estimated to have been 0.6% lower than in a scenario without fiscal consolidation. This impact may however be an upper bound: these simulations do not take account of the possibility of a sudden increase of financial distress following a major loss of confidence in the sovereign bonds of some euro area countries.Fiscal consolidation, sovereign risk spread, eurozone

Vegetation structure influences the retention of airfall tephra in a sub-Arctic landscape

Vegetation cover mediates a number of important geomorphological processes. However, the effect of different vegetation types on the retention of fine aeolian sediment is poorly understood. We investigated this phenomenon, using the retention of fine, pyroclastic material (tephra) from the 2011 eruption of the Grímsvötn volcano, Iceland, as a case study. We set out to quantify structural variation in different vegetation types and to relate structural metrics to the thickness of recently deposited volcanic ash layers in the sedimentary section. We utilised a combination of vegetation and soil surveys, along with photogrammetric analysis of vegetation structure. We found that indices of plant community composition were a poor proxy for vegetation structure and were largely unrelated to tephra thickness. However, structural metrics, derived from photogrammetric analysis, were clearly related to variations in tephra layer thickness at a landscape scale and tephra layers under shrub patches were significantly thicker than those outside the shrub canopy. We therefore concluded that: a) vegetation cover was a critical factor in the retention of fine aeolian sediment for deposit depths up to few centimetres; b) structural variation in vegetation cover played a major role in determining the configuration of tephra deposits in the sedimentary section. These findings have implications for the analysis of ancient volcanic eruptions and archaeological/palaeoenvironmental reconstructions based on the interpretation of tephra deposits. Furthermore, they present the possibility that the detailed form of tephra layers may be used as a proxy for palaeo vegetation structure. National Science FoundationThis is the author accepted manuscript. It is currently under an indefinite embargo pending publication by SAGE Publications

Recommendations of the Stiglitz-Sen-Fitoussi Report: A few illustrations

In September 2009 the Stiglitz-Sen-Fitoussi Commission submitted its report on the measurement of economic performance and social progress. The report is based on a large body of applied research work conducted in recent years in various fields of the economic and social sciences. Some of this research work proposes composite well-being indicators more appropriate than GDP. A parallel trend rather favours the construction of dashboards, i.e. sets of indicators designed to provide an understanding of the several facets of economic performance and quality of life. Without neglecting the interest of constructing composite indicators, the commission strongly emphasized the multidimensional nature of well-being. To address this multidimensional nature, it did not propose its own ready-made dashboard. The report must rather be read as providing guidelines to be followed for constructing such a dashboard. This dossier outlines the main lessons to be learned from a comparison between France and a few other countries with the same level of development, as measured against the criteria used by the Stiglitz Commission. The use of alternative standard of living indicators involves a few reclassifications across countries but without really calling into question the apparent advance of the United States. However, living conditions indicators do show far more marked contrasts in the areas of health, education, the risks of unemployment and poverty, and security. Contributions to the problem of climatic sustainability can be up to three times greater from one country to the next. As for economic sustainability, the indicator proposed by the commission suggests that this sustainability remains warranted, although with a fairly small safety margin in several countries.Stiglitz-Sen-Fitoussi report, measurement of well-being, international comparison, quality of life, sustainable development, economic growth

Optimising shape analysis to quantify volcanic ash morphology

AbstractAccurate measurements of volcanic ash morphology are critical to improving both our understanding of fragmentation processes and our ability to predict particle behaviour. In this study, we present new ways to choose and apply shape parameters relevant to volcanic ash characterisation. First, we compare shape measurements from different imaging techniques, including cross-sectional (2-D) and projected area images, and discuss their respective applications. We then focus on specific information that can be obtained from shape analysis of 2-D images. Using cluster analysis as an unbiased method to identify key controls on particle morphology, we find that four shape parameters – solidity, convexity, axial ratio, and form factor – can effectively account for the morphological variance within most ash samples. Importantly, these parameters are scaled to values between 0 and 1, and therefore contribute evenly to discrimination diagrams. In particular, co-variation in convexity and solidity can be used to distinguish different juvenile ash components based on characteristic bubble properties. By reducing observations of natural samples to simplified ash geometries, we quantify morphological changes associated with variations in the relative size and shape of bubbles and particles. Using this relationship, we assess the potential application of size-dependent shape analysis for inferring the underlying bubble size distribution, and thus the pre-fragmentation conditions. Finally, we show that particle shape analysis that includes the full range of available grain sizes can contribute not only measurements of particle size and shape, but also information on size-dependent densities

The New Version of the Model MZE, Macroeconometric Model for the Eurozone

This paper presents the main improvements carried out to the macroeconometric model MZE since its creation in 2003. We have back-calculated the series over the period 1980-1995, in order to make the model more stable. To our knowledge, this paper is the first application of Kllians (1998) method to estimate coefficients and centered confidence intervals for an operational macroeconometric model. The new coefficients enable to get less inflationary responses to macroeconomic shocks than the previous version of MZE. The study is more nuanced and rigorous thanks to the confidence intervals around the main scenarios. It is thus possible to check the significance of the results at any horizon. At last, the new version of MZE enables to find conventional responses to international shocks, like the inflationary effect of a rise in oil prices or the delayed impact of a depreciation of the euro on the improvement of the trade balance.Macroeconometric modelling, Forecasting, Confidence interval, Bootstrap

The Environmental Effect of Green Taxation: the Case of the French "Bonus/Malus"

At the beginning of 2008 was introduced in France a feebate on the purchase of new cars called the Bonus/Malus. Since January 2008, less polluting cars benefit from a price reduction of up to 1,000 euros, while the most polluting ones are subject to a taxation of 2,600 euros. We estimate the impact of this policy on carbon dioxide emissions in the short and long run. These emissions depend on the market shares and the average emissions per kilometer of each car, but also on their manufacturing, car fleet size and the average number of kilometers travelled by their owners. We first develop a simple tractable model that relates car choice and mileage. We then estimate this model, using both the exhaustive dataset of car registrations and a recent transportation survey which provides information on individual journeys. We show that if the shift towards classes benefiting from rebates is spectacular, the environmental impact of the policy is negative. The reform has notably increased sales, leading to an important increase in manufacturing and travelling emissions. We thus stress that such policies may be efficient tool for reducing CO2 emissions since consumers do react to such financial incentives, but should be designed with care to achieve their primary goal.environmental taxation, automobiles, carbon dioxide emissions, policy evaluation