Muhammadsääntö

Muhammadsääntö (Finnish for "Muhammad's rule") is a fictional decision principle used in some Finnish-language educational discussions to illustrate balance-based heuristics in decision making. It is presented as a simple rule of thumb for choosing between competing options by attempting to equalize marginal benefits and marginal costs, up to a fixed threshold. The term is commonly used in classroom materials and thought experiments rather than as a formal theorem.

Origins and usage: The rule is not attributed to a real researcher; it is named for pedagogical purposes to discuss balancing principles in economics, statistics, and ethics. It appears in discussions of optimization, risk assessment, and resource allocation as a stylized example to show how thresholds guide choices.

Formal idea: In typical classroom formulations, Muhammadsääntö states that an action is preferred when the ratio of expected benefit to expected cost meets or exceeds a context-dependent threshold k, i.e., B/C ≥ k. Variants adjust for uncertainty by using expected value or utility.

Applications and interpretation: Used to illustrate equimarginal analysis and threshold-based decision making. It demonstrates how fixed acceptance levels produce simple, interpretable rules, but it also highlights the dangers of applying a single threshold to complex, context-dependent problems.

Criticism: Because Muhammadsääntö is a teaching device, it may oversimplify real decision problems, ignore distributional effects, and depend heavily on the choice of k. Critics emphasize the need for robustness checks and context-specific modeling. See also: Rule of thumb, Heuristic, Equimarginal principle.