Tideman

Tideman is a surname. It is most widely associated with Nicolaus Tideman, an American economist who introduced the ranked pairs voting method in 1987, sometimes called the Tideman method.

The ranked pairs method is a Condorcet method for selecting a single winner in elections. It analyzes all pairwise candidate comparisons, computes the margin of victory in each, and orders pairs from strongest to weakest by that margin.

Starting with no locked pairs, the method processes pairs in that order and locks in a pair if adding it does not create a cycle in the graph of locked-in victories.

Once all pairs have been considered, the winner is identified as the candidate who is a source in the locked graph (i.e., who has no incoming locked edges). The method favors stronger head-to-head victories and avoids cycles, yielding a final ranking or winner that reflects the strongest preferences observed in pairwise contests.

Relation to the broader field: The Tideman method is widely discussed in social choice theory as an alternative to other Condorcet methods, such as the Schulze method. It has been implemented in election software and used in theoretical studies as part of research into how best to aggregate individual rankings into a single decision. Tideman's work contributed to the development and analysis of voting systems and their properties in collective decision-making.