Some interesting visualizations have been published by Standard Chartered in the new report Local Markets Compendium.
This large tree map shows the size of total government debt outstanding across 161 countries worldwide. Each rectangle shows the size of each bond market, and the color of each square shows the debt-to-GDP ratio for that country.
In 2002, the world government bond market was $22.98 trillion in size. As of the end of 2012, it had reached $57.90 trillion.
This map shows what portion of each government’s debt is held by foreign investors.
And this map shows government debt as a percentage of GDP.