Code to Create the Trade Share matrix used in:
 The Elasticity of Trade: Estimates and Evidence, with Ina Simonovska.
Journal of International Economics, 92(1): 34-50. January 2014. 2015 Winner of The Bhagwati Award (selected by the JIE Editorial Board as the best article published in the JIE during 2013 and 2014).
 Trade models, trade elasticities, and the gains from trade, with Ina Simonovska.
No. w20495. National Bureau of Economic Research, 2014.
The main driver file is make_tradeshare.m
It calls a STATA file adjust_trade.do wihch downloads data from the world trade flows database:
Feenstra, R. C., R. E. Lipsey, H. Deng, A. C. Ma, and H. Mo (2005): “World trade flows: 1962-2000,” Tech. rep., National Bureau of Economic Research.
We obtain trade flows for year 2004 at the SITC-4-digit level for each country-pair in the dataset from an update to Feenstra et al. (2005) using UN Comtrade data.
We then converted the trade flows to ISIC codes and then construct_tradematrix.m aggregates the data to the only the manufacturing sector. This stores aggregate trade flows in the following way, each column is an importer, a row is an exporter.
The file impute_output_data.m then constructs an imputation of gross output for the countries we did not have data for. The details are in that file.
Then the file aggregate_drop.m makes some adjustments (either dropping or aggregating (e.g. China and Hong Kong) countries). This is also setup to take different cuts, e.g. only the top 30 countries.
The file construct_tradeshare.m constructs the trade share matrix. Again this is organized so that each column is an importer, a row is an exporter. The sum down a column should (and does) equall one.
The file output_data.xlsx has the country names, identifiers, and the output data used.
Finallly, the file creates gravity variables and then outputs a data set that is usable in my companion code repository on Gravity Estimation. It reads in the set of distance, border from the file dist_cepii.dta and then after adjustment the gravity data set is a N^2 by 5 (where N is the number of countries) in the following order, importer code, exporter code, normalized bilateral trade share, bilateral distance, and a contignuity dummy.