First published anonymously in 1798, this book predicted a grim future, as population increased. While it was not the first book on population, it was revised for over 28 years and has been acknowledged as the most influential work of its era. A key portion of the book was dedicated to what is now known as Malthus' Iron Law of Population. This theory suggested that growing population rates would contribute to a rising supply of labour that would inevitably lower wages. In essence, Malthus feared that continued population growth would lend itself to poverty and famine.