EFI Database also includes a “cleaned” series, in a variable named QUANTITY. As part of the data cleaning process, EFI staff standardized measurement units—in particular, they converted all physical quantities to cubic meters—and corrected decimal place errors and other obvious mistakes in the QORIG series.<sup>6</sup> In section 2.2 we explain how we used the QUANTITY variable to develop a relative measure of trade flow discrepancies, which served as the dependent variable in our econometric models. In section 5.1 we explain how we used the QORIG variable to develop measures of potential measurement error, which we included in the explanatory variables.

The product categories in the database are relatively broad aggregates of SITC codes. They correspond to the product definitions used by the U.N. Food and Agriculture Organization in its online FAOSTAT Forestry database (apps.fao.org/page/collections?subset=forestry). “Sawnwood” is such a category. We selected sawnwood as the focus for our analysis because Romania imports and exports relatively little of other primary forest products. Romania has historically exported a substantial amount of wood furniture, but the EFI Database includes data on trade of wood furniture only for two years, 1999-2000. For most products, including sawnwood, the database includes data separately for nonconiferous (NC) and coniferous (C) products.<sup>7</sup> We analyzed the two subcategories separately. Appendix 1 shows the SITC and U.N. codes included in the NC and C sawnwood product categories in the database.

The EFI Database includes nearly four decades of data, 1962-99. Our analysis covers a shorter period, 1982-97, due to the more limited availability of some of the explanatory variables in the econometric model. The database contains data on Romanian trade flows mainly from 1990 forward. Changes in national boundaries during the 1990s affect the definitions of several Romanian trading partners. The database includes Germany as a single country since 1991 and as two countries, West Germany (“Germany FR”) and East Germany (“Germany DR”) in prior years. It includes Czechoslovakia, Yugoslavia (“ex-Yugoslavia”), and the Soviet Union (“ex-USSR”) as single countries before 1993; from 1993 forward, it includes the Czech Republic, Slovakia, Macedonia, Bosnia and Herzegovina, Croatia, Slovenia, Yugoslavia (i.e, Serbia and Montenegro), and the individual republics of the former Soviet Union (Russian Federation, etc.) as separate countries. It reports data separately for Belgium and Luxembourg only after 1998.

# **2.2 A relative measure of discrepancies in trade statistics**

We developed a relative measure of discrepancies in trade statistics. Denote imports and exports by the following variables: Then the relative discrepancy is defined as:

> 6 They also made an effort to fill in missing data on physical quantities, by dividing data on the value of trade by unit values for other importers or exporters. We excluded these constructed estimates from the data we analyzed.

> 7 Nonconiferous trees are flowering plants (angiosperms). They are often referred to as broad-leaved or hardwood trees. Coniferous trees are cone-bearing plants (gymnosperms). They are often referred to as needleleaved or softwood trees.

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