An informal economy (informal sector or shadow economy) is the part of any economy that is neither taxed nor monitored by any form of government.
The size of Japan's informal economy is estimated to be 9.6% which represents approximatly $604 billion at GDP PPP levels.
Japan's data is highlighted in the table below, use the filter and sort order options to allow easy comparison with other countries.
Data source: Quarterly Informal Economy Survey (QIES) by World Economics, London