# On Parameterized Complexity of Liquid Democracy

arXiv: https://arxiv.org/abs/2011.14192 · HTML: https://mlsanity.com/paper/2011.14192/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 28 Nov 2020.

## Built on by (most cited first, 3 of 3)

- [When Can Liquid Democracy Unveil the Truth?](https://mlsanity.com/paper/2104.01828/) (2021)
- [As Time Goes By: Adding a Temporal Dimension Towards Resolving Delegations in Liquid Democracy](https://mlsanity.com/paper/2307.12898/) (2023)
- [Computation and Bribery of Voting Power in Delegative Simple Games](https://mlsanity.com/paper/2104.03692/) (2021)

## Abstract (arXiv)

In liquid democracy, each voter either votes herself or delegates her vote to some other voter. This gives rise to what is called a delegation graph. To decide the voters who eventually votes along with the subset of voters whose votes they give, we need to resolve the cycles in the delegation graph. This gives rise to the Resolve Delegation problem where we need to find an acyclic sub-graph of the delegation graph such that the number of voters whose votes they give is bounded above by some integer λ. Putting a cap on the number of voters whose votes a voter gives enable the system designer restrict the power of any individual voter. The Resolve Delegation problem is already known to be NP-hard. In this paper we study the parameterized complexity of this problem. We show that Resolve Delegation is para-NP-hard with respect to parameters λ, number of sink nodes and the maximum degree of the delegation graph. We also show that Resolve Delegation is W[1]-hard even with respect to the treewidth of the delegation graph. We complement our negative results by exhibiting FPT algorithms with respect to some other parameters. We finally show that a related problem, which we call Resolve Fractional Delegation, is polynomial time solvable.