Parkinson's Law states that work expands to fill the time available for its completion.
Where it comes from
British naval historian C. Northcote Parkinson opened a satirical essay in The Economist in 1955 with the line "Work expands so as to fill the time available for its completion."¹ His real target was bureaucracy. He noted, for example, that staff at the British Admiralty kept growing while the Royal Navy's fleet shrank. The essay grew into a bestselling book.² Psychologists Judith Bryan and Edwin Locke later found in a laboratory experiment that people given more time for a task worked more slowly, a result they linked to goal setting.³
Where it goes wrong
The law is often quoted to justify ever-tighter deadlines. Too little time has costs of its own, from errors to exhaustion. Parkinson's sharper point was about organizations that add people and paperwork whether or not the work requires them.
Talent Takeaway
Give meetings and internal tasks a clear time box, such as 25 minutes instead of an hour, and set deadlines that are ambitious and realistic. Then notice what the extra time used to buy you.
¹ Parkinson, C. N. (1955, November 19). Parkinson's law. The Economist.
² Parkinson, C. N. (1957). Parkinson's law, and other studies in administration. Houghton Mifflin.
³ Bryan, J. F., & Locke, E. A. (1967). Parkinson's law as a goal-setting phenomenon. Organizational Behavior and Human Performance, 2(3), 258–275.
Further reading: Locke, E. A., & Latham, G. P. (2002). Building a practically useful theory of goal setting and task motivation: A 35-year odyssey. American Psychologist, 57(9), 705–717.