The evidence I'm seeing suggests that the experiment is not yet yielding the expected results. Hence my suggestion of certain changes which could help it along.
Full-blown economics discussion, and what could spur the economy, is a large enough topic that I would not tackle it via a HN post.
Edit: The evidence I provided was that current legal framework is explicit enough in its treatment of corruption and yet corruption is still present which suggests that the problem is not in the rules.
Also, I don't like how you equate parallel economy to black economy. Those are different terms in Economics and the majority of economic transactions outside of regulations and laws are not bribes but a part of the informal sector (grey economy) [1]. And India is considered one of the countries with biggest grey sector in the world [2].
[1] - https://en.wikipedia.org/wiki/Informal_sector
[2] - http://www.ibtimes.com/india-has-second-highest-rate-shadow-...
The 'parallel economy' is a non-colored word for the non-white economy, which is is transactions that the government does not know about, usually referred to as the 'black economy'. If you do not like the use of the term, you may perhaps launch a petition to change the popular usage?