ceiling method
n.— «How does anyone administratively know how many hectares would be the right size? The only way one can arrive at such a figure is through a sophisticated technique known as the ceiling method, which means you look at the ceiling and conjure up a figure. The actual figure is best left to commercial considerations of the developer, bearing in mind economies (and diseconomies) of scale and scope.» —“Swinging socialist ’60s” by Bibek Debroy Indian Express (New Delhi, India) Apr. 6, 2007. (source: Double-Tongued Dictionary)