Fianna Fáil’s election manifesto, launched on Monday in Dublin, was not lacking in proposals, plans, pledges, or promises. The document, stretching to 196 pages, outlined a dizzying array of tax cuts and spending increases, as well as measures to build more houses, shorten hospital waiting lists, and deploy more gardaí. Under its watch, there would be a new government department to manage migration and security, while the NTMA would take responsibility for large-scale infrastructure projects. I could go on. And on. But you get the jist. But just what were the economic and budgetary assumptions underpinning the party’s grand proposals?…