Betteridge's law of headlines
GeneralAny headline that ends in a question mark can be answered by the word no.
The Collection
Laws
Named regularities and principles — the kind that explain a great deal in one sentence.
General 7
Campbell's law
GeneralThe more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor.
Hofstadter's law
GeneralIt always takes longer than you expect, even when you take into account Hofstadter's law.
Parkinson's law of triviality
GeneralOrganizations commonly give disproportionate weight to trivial issues. (C. Northcote Parkinson, 1957.)
Two species which compete for the same limited resource cannot coexist at constant population values.
Goodhart's law
GeneralAny observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.
Hanlon's razor
GeneralNever attribute to malice that which is adequately explained by stupidity.
Complex Systems 2
Gall's law
Complex SystemsA complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a working simple system.
Woods' theorem
Complex SystemsAs the complexity of a system increases, the accuracy of any single agent's own model of that system decreases rapidly.
Economy 5
Arrow's impossibility theorem
EconomyWhen voters have three or more distinct alternatives, no ranked voting system can convert the ranked preferences of individuals into a community-wide ranking while also meeting unrestricted domain, non-dictatorship, Pareto efficiency, and independence of irrelevant alternatives.
Gresham's law
EconomyBad money drives good money out of circulation — more precisely, if their exchange rate is set by law.
Coined 1858 by Henry Dunning Macleod; named for Sir Thomas Gresham (1519–1579).
Jevons paradox
EconomyIncreasing the efficiency of resource use can lead to higher overall consumption of that resource, rather than a reduction.
Say's law
EconomyProduction is the source of demand.
Wagner's law
EconomyThe development of an industrial economy will be accompanied by an increased share of public expenditure in gross national product.
Software 1
Lehman's laws of software evolution
SoftwareA set of laws describing how software systems change over time — most notably, that a program used in a real-world environment must continually adapt or it becomes progressively less useful, and that as it evolves its complexity increases unless work is done to reduce it.