Identifying base year for tax devolution is a challenge, says NK Singh

The 15th Finance Commission will have to use imagination and innovation to come up with the next devolution formula, says chairman NK Singh. He adds there are some complex challenges when it comes to determining the base year as the commission comes up with the next tax devolution formula.CNBC-TV18's Sapna Das tells us what kind of options the commission is dealing with regards to tax devolution formula, and what does the commission see as India’s biggest challenges in the coming years?