Christine Lagarde, managing director of the International Monetary Fund, U.S.
Christine Lagarde, managing director of the International Monetary Fund, U.S. Reuters

The Indian economy is expected to more than double in size by 2019 as compared to 2009, on the back of its policy reforms and improved business confidence, according to the International Monetary Fund (IMF) managing director Christine Lagarde.

In a speech that will be delivered at the Lady Sri Ram College in New Delhi, the IMF chief would speak about India's gross domestic product, which will exceed that of Japan and Germany combined in the next four years, when adjusting for differences in purchase prices between economies.

In addition to this, the output of Asia's third largest economy would exceed that of Russia, Brazil, and Indonesia — the next three emerging markets — combined.

India's growth comes as recovery in the global economy remains "too slow, too brittle, and too lopsided."

"In this cloudy global horizon, India is a bright spot. Recent policy reforms and improved business confidence have provided a booster shot to economic activity," the speech reads.

Based on India's new GDP measurement, the IMF expects India's growth to pick up to 7.2% in the financial year ending in March 2015 and accelerate further to 7.5% in the next fiscal year. At that pace, India will be the fastest growing large economy in the world.

She notes that higher growth rate is backed by the country's demographic features. More than 50% of India's population is currently below the age of 25 and more than 12 million people enter the labour market every year.

"By 2030, India is expected to have the largest labor force in the world. At more than one billion people of working age, India's labor force will be larger than the combined labor force in the United States, the Euro Area, and Indonesia," the speech states.

Lagarde will advocate "stronger economic frameworks" for the country to make its economy "more resilient, nimble, and ever more supportive of growth." She wants the country to have sound monetary and fiscal policies and a healthy financial sector to support growth.