The source of your goods export data for Ghana for 2014 and 2015 is not clear. According to your FAQ and Data pages, your export data source is COMTRADE as vetted by BACI. However, there are no COMTRADE data available for Ghana via the comtrade.un.org site (Ghana may not have reported data to COMTRADE for those years; the reason for the lack of data is not clear). You can look at Ghana COMTRADE country data [via https://comtrade.un.org/data] COMTRADE country availability data [or https://comtrade.un.org/data/da]; both show no data for Ghana for 2014 and 2015
=>Where, then, does this OEC data come from?
Your Ghana export value data for 2013 ($18.8 B) and 2012 ($16.6 B) are far off those reported for the same years by COMTRADE ($12.6 B and $15.76 B, respectively).
What accounts for this? If OEC sources from a source different from COMTRADE when no data from COMTRADE is available, you'd need to source that data. It is also unclear what BACI does when it "cleans" data (per your source note.
From your FAQ:
For historical SITC classification data, we use data from The Center for International Data from Robert Feenstra. For up to data HS classification data, we use data provided by UN COMTRADE.
http://atlas.media.mit.edu/en/resources/faqs/
From your data page:
For all of the HS data used throughout the site (1995 - 2014) we use the BACI International Trade Database2. The original data comes from the United Nations Statistical Division (COMTRADE), but is cleaned by the BACI team using their own methodology of harmonization.
http://atlas.media.mit.edu/en/resources/data/
=>Where, then, does this OEC data come from?
What accounts for this? If OEC sources from a source different from COMTRADE when no data from COMTRADE is available, you'd need to source that data. It is also unclear what BACI does when it "cleans" data (per your source note.
Refs re your data/ data descriptions: http://atlas.media.mit.edu/en/visualize/tree_map/hs92/export/gha/all/show/2013/ [use <> to access nearby years]
Re COMTRADE DATA
From your FAQ: For historical SITC classification data, we use data from The Center for International Data from Robert Feenstra. For up to data HS classification data, we use data provided by UN COMTRADE. http://atlas.media.mit.edu/en/resources/faqs/
From your data page: For all of the HS data used throughout the site (1995 - 2014) we use the BACI International Trade Database2. The original data comes from the United Nations Statistical Division (COMTRADE), but is cleaned by the BACI team using their own methodology of harmonization. http://atlas.media.mit.edu/en/resources/data/