pushing on a string
n.— «The attempt to pump money into the banking system failed, and as a result, the phrase “pushing on a string” was coined to describe the futility of inflationary policies in this environment.» —“Wisdom from Richard Russell on the Inflation/Deflation Topic” by Jay Taylor HoweStreet.com Nov. 21, 2005. (source: Double-Tongued Dictionary)
Further reading
What if, instead of being an inanimate object, a dictionary were alive? That’s the idea behind a lavishly illustrated new children’s book called The Dictionary Story (Bookshop|Amazon) by Oliver Jeffers and Sam Winston. This is part of a...
Jim in Columbia, South Carolina, has noticed sportscasters’ use of the phrase on the season with reference to a period of time. This construction shows up in the sports pages as early as the 1880s, first referring to a team’s revenue and...