New Delhi, Aug. 1 -- Two years is a reasonably long time for any new reform to be fully implemented. But the goods and services tax (GST), rolled out in July 2017, is still a work in progress. By now, most of its problematic aspects, such as the multiplicity of rate slabs and complexity of filing returns, ought to have been addressed. Yet, plenty of work still needs to be done. Apart from slab reduction, compliance simplification and a friendlier online transaction reporting interface, the GST needs a workable mechanism to check evasion. A recent report on the tax by the Comptroller and Auditor General of India (CAG) highlights these shortcomings. It draws special attention to the system's vulnerability to fraud by way of excess input tax credit claims-which are refunds of taxes already paid by input suppliers, GST being applicable only to the value added by a business or service provider. While there is no denying that the GST today is better than it was two years ago, the fact that some of its original goals remain elusive suggests the need for a course correction....