In Poroi, Xenophon examines the meaning of prosperity and its relationship to employment, consumption and expenditure in a way that no one else would until John Maynard Keynes wrote The General Theory of Employment, Interest and Money. The observations of Xenophon and Keynes agree on many points. This study strives to clarify Xenophon's importance as an economic thinker and the originator of the study of macroeconomics. Because the only readily available English translation of Poroi is Marchant's Loeb edition, it provides a contemporary and accessible rendering of the Greek into English. This critical edition also incorporates recent scholarship and remedies some difficulties in the critical apparatuses of earlier editions.