Who believed that famines are the result of "failure of entitlements"?

NCERT (2025-26): “2.2 Size and Growth of India’s Population … Lack of adequate means of transportation and communication as well as inadequate efforts on the part of the state were some of the factors responsible for famines. However, as scholars like Amartya Sen and others have shown, famines were not necessarily due to fall in foodgrains production; they were also caused by a ‘failure of entitlements’, or the inability of people to buy or otherwise obtain food. Substantial improvements in the productivity of Indian agriculture (specially through the expansion of irrigation); improved means of communication; and more vigorous relief and preventive measures by the state have all helped to drastically reduce deaths from famine.…”