                     Technical Documentation

Sources and Limitations

The data in this release are compiled from administrative records from the official 
U.S. import and export merchandise trade statistics.  The merchandise trade data are 
a complete enumeration of documentation collected by the U.S. Customs Service and 
are not subject to sampling error.  Quality assurance procedures are performed at 
every stage of collection, processing and tabulation; however, the data are still 
subject to nonsampling errors. These include undocumented shipments, timeliness, data 
capture errors and errors in the estimation of low-valued transactions.

Related party shipments are identified by an indicator, "R" for related or "N" for 
nonrelated, that is required on every transaction.  A major problem is the failure of 
importers and exporters, especially exporters, to report the indicator on their 
shipments.  No attempt is made to estimate the related party status of shipments with 
missing indicators; instead, they are categorized on the data tables as "unreported."  
Therefore, the ratios of related and unrelated party trade are understated.  

Users are advised to consider these limitations in their analysis of this data as they 
may affect the results. 


Definitions -- Related party trade:

Imports: As defined in Section 402(e) of the Tariff Act of 1930, related party trade 
includes transactions between parties with various types of relationships including 
"any person directly or indirectly, owning, controlling or holding power to vote, 6 
percent of the outstanding voting stock or shares of any organization." 

Exports: The Foreign Trade Statistics Regulations, 30.7(v), define a related party
transactions as one between a U.S. exporter and a foreign consignee, where either party 
owns, directly or indirectly, 10 percent or more of the other party.

Imports for Consumption: The import data shown in this report are imports for 
consumption that measure all merchandise that has physically cleared through Customs, 
either entering consumption channels immediately or after withdrawal from bonded 
warehouses under Customs custody or from Foreign Trade Zones.

Customs Value: The import data in this report are based on Customs value, generally 
defined as the price actually paid or payable for merchandise when sold for exportation 
to the United States, excluding U.S. import duties, freight, insurance and other charges 
incurred in bringing the merchandise to the United States.

F.A.S. Value: Exports are valued on a free alongside ship basis, which reflects transaction
price including inland freight, insurance and other charges incurred in placing the 
merchandise alongside the ship as the port of export.

Low Value Estimates: Import and export transactions below specific values are estimated
using factors based on the ratios of low-valued transactions to individual country totals 
for past periods.  Import transactions valued $2,000 dollars or less, excluding certain 
textile articles, and all export transactions valued $2,500 dollars or less are estimated.  

Re-exports: Exports of foreign merchandise that previously entered the U.S. Customs Territory 
and are exported in substantially the same condition as when imported. 

Inquiries related to these data may be directed to the Bureau of the Census, Foreign Trade 
Division, Special Projects Branch, Washington, D.C. 20233
Contact:  Kathleen J. Puzzilla
(301)-457-3251 or
kathleen_j_puzzilla@census.gov.