The appointment of Raghuram Rajan as head of the central bank offers a rare glimmer of light in monsoon-struck India.

Caught between sliding growth, a twin budget and current-account deficit and a plummeting rupee, the Indian economy is in one of its gloomiest periods since the 1991 crisis. The former chief economist for the International Monetary Fund has a big reputation in the capital markets. He should use his influence to lay out publicly what is needed to restore India’s battered macroeconomic credibility.

Mr Rajan’s arrival, however, is no turning point in India’s fortunes. From the return of Manmohan Singh as prime minister, to the selection of Palaniappan Chidambaram as finance minister, India has appointed a number of respected figures to its most prestigious policy roles. Yet these high-profile appointees have failed to halt India’s economic slowdown.