Transitivity
If you prefer A to B and B to C, consistency demands you prefer A to C.
What it means
A foundational axiom of rational choice requiring that preferences be internally consistent across pairwise comparisons. Together with completeness, it is what lets preferences be represented by a single utility ordering, so an agent can always identify a best option. Behavioral research documents systematic violations — driven by context, framing, and which attributes are salient in each comparison — which undermine the assumption that people have stable, well-ordered preferences. It matters because much of economic theory rests on transitivity, and its failure opens the door to money pumps and to preference-construction views of choice.
Examples
A consumer prefers laptop A to B on price, B to C on weight, and C to A on screen, ending in a circle no single ranking can capture.
A panel prefers candidate A to B on experience, B to C on team fit, and C to A on technical depth; every vote looks sensible, but the winner now depends on interview order.
If you would swap your bike for a kayak, the kayak for a tent, and the tent plus a fee for your bike, a dealer can walk you round that loop forever, charging every lap.
First described in Decision-theory axiom; violations by Tversky (1969).