ARVIND Subramaniam, the chief economic adviser to India's finance ministry, did not sound very confident in an article explaining the goods and services tax published in leading newspapers on Tuesday. Stating that the GST "has entered its last and critical phase" - that is, the determination of its rate structure - he said: "Now is the moment of truth when items will be assigned to the different GST slabs and the exact amounts of the cesses will be decided."

After explaining the various duty structures possible, he concluded: "Politics must yield outcomes that are passably good, otherwise they are not worth having. Can the GST Council, at this constitutional moment, deliver such an outcome? The country will be watching, oscillating between hope and anxiety."

The thoughtful economist - who once referred to the GST as "fiendishly, mind-boggingly complex to administer" but also called it a "game changing reform" whose passage would be a "major, historic achievement" - is a government spokesman worth taking seriously.