Massie died in Holborn, London on 1 November 1784. His life is shrouded in obscurity; his death is mentioned in a terse note in Gentleman's Magazine. We also know that he ceased writing or at least publishing twenty years before his death, and that some of his tracts were dedicated to statesmen of the period from whom he had little encouragement. Indeed, it was only after his death that Massie attracted a degree of recognition. Firstly, historians of economic thought are grateful that he spent some twelve years setting up a collection of some fifteen hundred tracts and treatises concerning the commerce, coin and colonies of Great Britain. Although the collection was sold in November 1760 and thereafter dispersed, Massie left a monument of his zeal in a compiled finding-list which he continued to revise and extend until December 1764 and which still serves today as a helpful guide to British economic literature before Adam smith.
From The Biographical Dictionary of British Economists in Oxford Reference.