I continue to like the U.N. as a topic, long-term. The market for U.N.-related topicals should grow over the very long haul as institutions of world government develop in order to take on serious (and possibly existential) problems which can only be coped with globally. Despite the present inadequacy, corruption, and ineffectiveness of the U.N., I view its reform and gradual strengthening as a gradual but irresistible trend.
South Korea, a nation of about 50 million people, is one of the fastest growing economies in the world. Currently, it is the world's 13th largest economy and eighth largest exporter. It's export-fueled economic growth has led to a miraculous explosion in its GDP, from almost nothing 50 years ago to about $1 trillion today. Annual GDP growth has averaged 4.2% over the last 5 years, reflecting a slowdown in 2009 due to the global financial crisis. Furthermore, South Korea may be the most rapidly aging nation on earth, as its 65+ population is expected to more than quadruple from 9% in 2005 to 38% in 2050. Obviously, this could pose economic challenges for the country, but it will almost certainly add to its stamp collecting population.
Information concerning printing quantities of stamps is often useful in determining which may turn out to be good investments. The StampSelector Scarce Stamp Quantities Issued List (SSSSQIL) currently includes over 9,700 listings of stamps and souvenir sheets with issuance quantities of 100,000 or less.