Soledad Zignago

Bio: Soledad Zignago is an academic researcher from Banque de France. The author has contributed to research in topics: Market share & Regional integration. The author has an hindex of 27, co-authored 101 publications receiving 4388 citations. Previous affiliations of Soledad Zignago include Centre d'Etudes Prospectives et d'Informations Internationales & BBVA Compass.

Notes on CEPII’s Distances Measures: The GeoDist Database

Abstract: GeoDist makes available the exhaustive set of gravity variables used in Mayer and Zignago (2005). GeoDist provides several geographical variables, in particular bilateral distances measured using citylevel data to assess the geographic distribution of population inside each nation. We have calculated different measures of bilateral distances available for most countries across the world (225 countries in the current version of the database). For most of them, different calculations of “intra-national distances” are also available. The GeoDist webpage provides two distinct files: a country-specific one (geo_cepii) and a dyadic one (dist_cepii) including a set of different distance and common dummy variables used in gravity equations to identify particular links between countries such as colonial past, common languages, contiguity. We try to improve upon the existing similar datasets in terms of geographical coverage, quality of measurement and number of variables provided.

BACI: International Trade Database at the Product-level

Abstract: We document BACI, our international trade database covering more than 200 countries and 5,000 products, between 1994 and 2006. Original procedures have been developed to reconcile data reported by almost 150 countries to the United Nations Statistics Division, which disseminate them via COMTRADE. When both exporting and importing countries do report, we have two different figures for the same flow, which is useful to reconcile in a single figure. Firstly, as import values are reported CIF (cost, insurance and freight) and the exports are reported FOB (free on board), CIF costs have to be estimated and removed from imports values to compute FOB import values. We regress the unit-values ratios reported for a given elementary flow by gravity variables and for years, and world median unit-value for each product category . The second step is an evaluation of the reliability of country reporting, based on the reporting distances among partners. We decompose the absolute value of the ratios of mirror flows using a (weighted) variance analysis, and an index is build for each country. These reporting qualities are used as weights in the reconciliation of each bilateral trade flow twice reported. Taking advantage of this double information on each flow, we end up with a large coverage of countries not reporting at a given level of the product classification with a special care in the treatment of unit-values. BACI is freely available to users of COMTRADE database in our webpage: http://www.cepii.fr/anglaisgraph/bdd/baci.htm

Notes on CEPII’s distances measures

Abstract: We have calculated and made available different measures of bilateral distances (in kms) available for most countries across the world (225 countries in the current version of the database). For most of them, different calculations of “intra-national distances” are also available. There are two distinct files: a country-specific one (geo_cepii.xls or geo_cepii.dta) and a bilateral one (dist_cepii.xls or dist_cepii.dta), including the set of different distance variables and common dummy variables used in gravity equations to identify particular links between countries such as colonial past, common languages, contiguity. A common use of those files is the estimation of gravity equations describing bilateral trade flows. We try to improve upon the existing similar datasets in terms of geographical coverage, measurement and number of variables provided.

BACI: International Trade Database at the Product-level The 1994-2007 Version

Abstract: This paper documents the construction of BACI, our international trade database, which covers more than 200 countries and 5,000 products, between 1994 and 2007. New approaches have been developed to reconcile data reported by almost 150 countries to the United Nations Statistics Division, collated via COMTRADE. When both exporting and importing countries report to Comtrade, we have two different figures for the same flow, so it is useful to reconcile these into a single figure. To do this, firstly, as import values are reported CIF (cost, insurance and freight) while exports are reported FOB (free on board), transport and insurance rates have to be estimated and removed from import values. We regress the observed CIF/FOB ratios for a given flow on gravity variables and a product-specific world median unit value. In a second step we evaluate the reliability of countries reporting. We decompose the absolute value of the ratios of mirror flows using a (weighted) variance analysis. These measures of the reliability of reported data are used as weights in the reconciliation of each bilateral trade flow which is reported twice. Taking advantage of this bilateral information on each flow, we end up with a large coverage of countries and more reliable data, especially in terms of unit-values. BACI is freely available online to users of COMTRADE database, in different product classifications.

BACI: International Trade Database at the Product-Level. The 1994-2007 Version

Abstract: This paper documents the construction of BACI, our international trade database, which covers more than 200 countries and 5,000 products, between 1994 and 2007. New approaches have been developed to reconcile data reported by almost 150 countries to the United Nations Statistics Division, collated via COMTRADE. When both exporting and importing countries report to Comtrade, we have two different figures for the same flow, so it is useful to reconcile these into a single figure. To do this, firstly, as import values are reported CIF (cost, insurance and freight) while exports are reported FOB (free on board), transport and insurance rates have to be estimated and removed from import values. We regress the observed CIF/FOB ratios for a given flow on gravity variables and a product-specific world median unit value. In a second step we evaluate the reliability of countries reporting. We decompose the absolute value of the ratios of mirror flows using a (weighted) variance analysis. These measures of the reliability of reported data are used as weights in the reconciliation of each bilateral trade flow which is reported twice. Taking advantage of this bilateral information on each flow, we end up with a large coverage of countries and more reliable data, especially in terms of unit-values. BACI is freely available online to users of COMTRADE database, in different product classifications.

Gravity Equations: Workhorse,Toolkit, and Cookbook

Abstract: This chapter focuses on the estimation and interpretation of gravity equations for bilateral trade. This necessarily involves a careful consideration of the theoretical underpinnings since it has become clear that naive approaches to estimation lead to biased and frequently misinterpreted results. There are now several theory-consistent estimation methods and we argue against sole reliance on any one method and instead advocate a toolkit approach. One estimator may be preferred for certain types of data or research questions but more often the methods should be used in concert to establish robustness. In recent years, estimation has become just a first step before a deeper analysis of the implications of the results, notably in terms of welfare. We try to facilitate diffusion of best-practice methods by illustrating their application in a step-by-step cookbook mode of exposition.

Notes on CEPII’s Distances Measures: The GeoDist Database

Abstract: GeoDist makes available the exhaustive set of gravity variables used in Mayer and Zignago (2005). GeoDist provides several geographical variables, in particular bilateral distances measured using citylevel data to assess the geographic distribution of population inside each nation. We have calculated different measures of bilateral distances available for most countries across the world (225 countries in the current version of the database). For most of them, different calculations of “intra-national distances” are also available. The GeoDist webpage provides two distinct files: a country-specific one (geo_cepii) and a dyadic one (dist_cepii) including a set of different distance and common dummy variables used in gravity equations to identify particular links between countries such as colonial past, common languages, contiguity. We try to improve upon the existing similar datasets in terms of geographical coverage, quality of measurement and number of variables provided.

Estimating Trade Restrictiveness Indices

Abstract: The objective of this paper is to provide indicators of trade restrictiveness that include both measures of tariff and nontariff barriers for 91 developing and industrial countries. For each country, the authors estimate three trade restrictiveness indices. The first one summarizes the degree of trade distortions that each country imposes on itself through its own trade policies. The second one focuses on the trade distortions imposed by each country on its import bundle. The last index focuses on market access and summarizes the trade distortions imposed by the rest of the world on each country's export bundle. All indices are estimated for the broad aggregates of manufacturing and agriculture products. Results suggest that poor countries (and those with the highest poverty headcount) tend to be more restrictive, but they also face the highest trade barriers on their export bundle. This is partly explained by the fact that agriculture protection is generally larger than manufacturing protection. Nontariff barriers contribute more than 70 percent on average to world protection, underlying their importance for any study on trade protection.

The Puzzling Persistence of the Distance Effect on Bilateral Trade

Abstract: One of the best-established empirical results in international economics is that bilateral trade decreases with distance. Although well known, this result has not been systematically analyzed before. We examine 1,467 distance effects estimated in 103 papers. Information collected on each estimate allows us to test hypotheses about the causes of variation in the estimates. Our most interesting finding is that the estimated negative impact of distance on trade rose around the middle of the century and has remained persistently high since then. This result holds even after controlling for many important differences in samples and methods.