For a research project at the German Institute of Global and Area Studies in Hamburg I am working with export trade value data for Commodity 33101 (CRUDE PETROLEUM) on SITC Rev.1 for all countries and need to compute its ratio to total exports and GDP. Comtrade trade value is given in USD, net weight in kg. I have noticed that different oil prices are used for different countries in a certain year (according to my calculations of trade value/quantity units). As I need to calculate own trade value data for the years with missing Comtrade data (based on export data from the UN Statistical Yearbooks given in net weight), I need to know how Comtrade derives the trade value in USD from a given trade quantity. Does anyone know which oil prices are used for this calculation or where to find this information?

Thanks 

Comtrade tries to estimate quantity or netweight only if country does not report them. That is the reason why unit value varies between reporting countries (or even within the same reporting country; depends on trade flow, partner country, etc).

 At part of estimation procedure, Comtrade may use Standard Unit Value (SUV; generated from historical data) to estimate quantity/netweight.

 The following SUV are used for Imports (netweight):

code year SUV ($/kg)
33101 2004 0.2708
33101 2005 0.2708
33101 2006 0.2708
33101 2007 0.4732

For an example, if country reports import of Crude Petroleum for $500000 in 2007, but it does not report netweight, Comtrade will estimate netweight with the following calculation 5000000 / 0.4732  = 10566356 kg

 

It would be good if Comtrade indicated where netweights have been calculated from values.

Any estimation is footnoted. You can access it on "View Footnotes" link in data query result.

For an example:

Selected classification: SITC Rev.1
Selected commodities: 33101 (Crude petroleum)
Selected reporters: All
Selected years: 2006
Selected partners: World
Selected trade flows: Import

Result is http://comtrade.un.org/db/dqBasicQueryResults.aspx?cc=33101&px=S1&y=2006&p=0&rg=1&so=1001&qt=n
and Footnote is http://comtrade.un.org/db/dqBasicQueryFnResults.aspx?cc=33101&px=S1&y=2006&p=0&rg=1&so=1001&qt=n

However, we understand that sometimes it is not clearly marked (noted for further improvement)

Thanks very much for your answer!

Could you also tell me where to find the complete list of SUV used for Petroleum Exports (netweight) for all years and countries?

Thanks a lot.
 

I'll send you via email. Please note that the table is provided only for internal use.

Standard Unit Value is generated once a year in December based on reported data on that year. SUV is available for 6 digit HS by year, trade flow and recommended quantity unit. It is not available by reporting country.

SUV is used to detect extreme unit value and also used in quantity estimation.

Thanks so much for all you help!

Where could I find SUV for 2004 through 2008 commodity code 3603