Tirthankar Roy suggests that the famines were due to environmental factors and inherent in India's ecology. Roy argues that massive investments in agriculture were required to break India's stagnation, however, these were not forthcoming owing to the scarcity of water, poor quality of soil and livestock and a poorly developed input market which guaranteed that investments in agriculture were extremely risky. After 1947, India focused on institutional reforms to agriculture however even this failed to break the pattern of stagnation. It wasn't until the 1970s when there was massive public investment in agriculture that India became free of famine, although Roy is of the opinion that improvements in the market efficiency did contribute to the alleviation of weather-induced famines after 1900, an exception to which is the Bengal famine of 1943.