NITI Aayog Vice Chairman Ashok Kumar Lahiri on Friday said India must significantly increase its investment rate to sustain its growth momentum, stressing that investment is as important as consumption in generating demand and driving economic growth. Speaking at the launch of NITI Aayog's Investment Friendliness Index for states, Lahiri said that while India has emerged as the world's fastest-growing major economy in recent years, much more needs to be done to accelerate growth.