Getting Straight Data on Trade and FDI for Revealed Comparative Advantage

I recently read the Asia Society's report on Chinese Direct Investment in California and perused the Rhodium Group's China Investment Monitor.  Both products are excellent rundowns of where Chinese investors find the US economy to be most attractive.  Both of these sources got me thinking about the relationship between trade data and FDI in the US.  

Trade data should be easy to compile if sources agree on computation methodologies.  I'll forgo the US Census Bureau's USA Trade because it charges a subscription fee.  The stats at USITA's TradeStats Express are free and meet my needs.  The UN Comtrade Database purports to be a comprehensive source of worldwide merchant trade data but I don't know how reliable it is for developing countries.  

Figuring FDI for any country ought to be straightforward.  After all, you'd expect a single country to report the same data sets to every international organization in which it holds membership.  The difficulty comes when those international organizations change their definitions of FDI and end up with different methods of collection and assessment.  The OECD has good stats on FDI and the IMF has a complex methodology for defining FDI.  The UN Conference on Trade and Development harmonizes the IMF and OECD approaches to measuring FDI.  I looked at the BIS stats page but found nothing obvious for FDI.  

I mention these sources because I want to discover whether trade data determines a revealed comparative advantage (RCA) that will attract more FDI.  The World Bank has a handy-dandy RCA calculator called WITS and UNESCAP has a good RCA definition.  I suspect there is a relationship between a country or region with a high RCA and a high inflow of FDI, presumably because sophisticated multinational investors want to invest in a region that has a disproportionately high share of the world market for a given set of goods.  I can't prove this yet with data, so I'm thinking out loud to signal the start of my research effort.  I plan to use the US as my test case and start with an analysis of my favorite sectors - defense/aerospace, logistics, renewable energy, and natural resources - to see if this relationship holds in my home country.  

Foreign ownership of US Treasury securities has long been a vote of confidence in the US economy.  I want to discover whether the FDI demand for the US's trade RCA justifies this confidence.  Watch this space for the official Alfidi Capital special report, coming whenever I get through the rest of the stuff I have to write about.