Optimism about the Indian economy makes it all the more necessary for the country to be prepared to face competition from nations like China and the United States, Wipro Chairman Azim Premji said today.India could well be the world's third largest economy after the US and China in less than 30 years from now. "However, we have to be fully prepared to face intense competition from these countries", he said, addressing the CII conference on "Re-energising India Inc Challenges" today."This huge sense of optimism, backed by a strong cash flow, is going to make a difference to the global market", he said.While quality, technology and cost effectiveness are short-term drivers for growth, long-term factors like demographic shifts, as in the case of India, could herald economic transformation, Premji said.India, where the young will represent the largest percentage of population in contrast to other developed countries, should "capitalise on this unprecedented opportunity for success and growth", he stressed.Utilising the youth could place India in a totally different league in economic transformation, he said.For achieving this, leadership at multiple levels, from the personal to the enterprise and social level is essential, he said.