Tax revenues across the country seem to have been boosted by demonetisation. Source.

The combined VAT collections of 23 states, which have provided data to the Centre, was up 18.1% in November, suggesting strong sales. For December, data is available for 17 states and that shows a rise in tax on the sale of goods at 8.9%.

The data substantiates the central government’s claims that demonetisation has had a positive impact on revenue collection.

The Centre’s own revenues were up sharply in November. Among the big states, only West Bengal reported a VAT contraction of 7.84% in December.

At a national level, indirect tax collection grew by 23.9% in the period Apr-Jan.

What's interesting is that clearly, even the Delhi govt didn't expect this windfall. On Jan 5th, Sisodia said that revenues were sharply affected by demonetisation and he predicted that revenues would be down by 24% with a further fall in Jan and Feb.

Would you have any data to suggest that this is because of the decreased VAT policy? In the previous year, there was an increase of only 2% in tax collections...so why didn't this policy spur greater collections then?