The Economic Conditions of North-Eastern Siam is the report of the first economic survey of Isan, conducted by Reginald Stuart Le May in 1929. Prior to 1929, not much was known of neglected Northeast Siam, previously called Laos. The population, almost 4 million, 1/3rd of the Kingdom’s, was primarily ethnically Lao and Khmer. Le May’s work, the result of provincial-level questionnaires, provides foundational knowledge of the contours of economic life in this neglected region just as Siam’s 1932 constitutional revolution took place. Leedom Lefferts wrote the introduction and compares the work with Carle C. Zimmermann’s Siam: Rural Economic Survey 1930-1931