# Reverse Sequential Proportional Approval Voting Rule: Proportionality and Approximation Guarantees

arXiv: https://arxiv.org/abs/2609.35331 · HTML: https://mlsanity.com/paper/2609.35331/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 13 of its 21 references that are in the map.
- First posted on arXiv 28 Sep 2026.

## Builds on (most cited first, 13 of 13)

- [Justified Representation in Approval-Based Committee Voting](https://mlsanity.com/paper/1407.8269/) (2014)
- [Multi-Winner Voting with Approval Preferences](https://mlsanity.com/paper/2007.01795/) (2020)
- [Finding a Collective Set of Items: From Proportional Multirepresentation to Group Recommendation](https://mlsanity.com/paper/1402.3044/) (2014)
- [Computational Aspects of Multi-Winner Approval Voting](https://mlsanity.com/paper/1407.3247/) (2014)
- [Proportional Rankings](https://mlsanity.com/paper/1612.01434/) (2016)
- [Online Approval Committee Elections](https://mlsanity.com/paper/2202.06830/) (2022)
- [Proportionality Degree of Multiwinner Rules](https://mlsanity.com/paper/1810.08799/) (2018)
- [Approval-Based Committee Voting in Practice: A Case Study of (Over-)Representation in the Polkadot Blockchain](https://mlsanity.com/paper/2312.11408/) (2023)
- [Phragm'en's and Thiele's election methods](https://mlsanity.com/paper/1611.08826/) (2016)
- [Dynamic Proportional Rankings](https://mlsanity.com/paper/2105.08043/) (2021)
- [Ties in Multiwinner Approval Voting](https://mlsanity.com/paper/2305.01769/) (2023)
- [Robustness of Greedy Approval Rules](https://mlsanity.com/paper/2208.00750/) (2022)
- [An Experimental Comparison of Multiwinner Voting Rules on Approval Elections](https://mlsanity.com/paper/2401.11870/) (2024)

## Abstract (arXiv)

We study the Reverse Sequential Proportional Approval Voting Rule (RevSeqPAV) in approval-based committee elections. Despite its historical prominence and practical use, its properties and guarantees are much less understood than those of Sequential PAV. We analyze it along two dimensions: proportional representation (measured by Extended Justified Representation, its approximations, and proportionality degree) and approximation of the maximum PAV score of instances. We first establish strong negative results for general, unrestricted election instances and then identify settings in which the rule provides meaningful fairness and optimization guarantees.