THE global shadow, the informal economy, remains huge despite rapid strides in digital payments.

This is frustrating for developed and emerging-nation governments that wish to claw in as much tax as possible to meet expenditure and cut borrowings.

It is exceedingly difficult to accurately quantify the size of the shadow, the underground economy. People involved in it include builders, artisans, cleaners, gardeners, vendors and others who receive cash and either pay no tax, or only a portion to the Inland Revenue. Legal and illegal immigrants who cannot obtain formal taxed and social insurance jobs also tend to be participants in the informal economy. Others are criminals such as drug dealers, pimps and small-time arms traders.