In 1816, the Year Without a Summer (caused by the 1815 eruption of Mount Tambora in Indonesia) caused famine by disastrously reducing crop yields. Reduced standard of living and food shortages due to poor harvests led to riots. But the ceiling price of 80 shillings a quarter for domestic grain was so high that, between 1815 and 1848, it was never reached. David Ricardo, however, espoused free trade so that Britain could use its capital and population to its comparative advantage.