WINNING THREE SEATS IN THE PHILIPPINE PARTY LIST SYSTEM

Republic Act 7941, the existing law on the party list system in the Philippines allows a registered Party List group to win up to three seats. We claim that it is possible to determine the minimum number of party list votes in order to win three seats.

The existing seat allocation formula for the Philippine party list system as promulgated by the Supreme Court in 2009 has three rounds of seat allocation. In the first round, one seat is awarded to the party list groups that obtain at least two percent (2%) of the total party list votes counted nationwide.We may call these party list groups that are winners in the first round as the Two-Percenters.

Additional number of seats, the maximum number of which is two, will be awarded to the Two-Percenters in the second round. To determine the number of additional seats for a Two-Percenter the following steps are  to be done:  

1.  the remaining number of party list seats is computed by subtracting the seats that were allocated in the first round from the total number of Party List seats that are available which is 20% of the total number of members in the House of Representatives.
2. The remaining number of party list determined in Step 1 shall be multiplied to the percentage share of votes obtained by each of the Two-Percenters.
3. The whole number of the product obtained in Step 2 is equivalent to the number of additional seats to be given to a Two-Percenter which cannot exceed two seats.

Thus, in order for a Two-Percenter to win three seats in the product of  the percentage share of its votes and the remaining number of seats shall be at least two (2).

Therefore, a Party List group with at least two  times its vote share divided by the remaining number of seats shall win three seats.

For example, if the remaining number of seats after the first round is 40, then a party list group that is targetting three seats shall have 2/40 or 5% of the total party list votes.

If the total number of party list votes is 30 million, then a party list group that hopes to win three seats shall target at least 1.5 million votes.

If the remaining number of seats after the first round is 45 and the total number of party list votes (TPLV) is 33 million, then a party list needs to have at least 1.466,667 votes to win three seats.

See the table below for other possible scenarios.

by Felix P. Muga II
Associate Professor, Mathematics Department, Ateneo de Manila University
Senior Fellow, Center for People Empowerment in Governance

The Mathematics of Politics (specifically Party List)