As discussed in a previous thread, the new Israeli government is based on an agreement that includes a commitment to raise the electoral threshold from 2% to 4%. What impact might this have?
In a working paper (of which I will become co-author), Taagepera has developed a logical model that suggests the number of parties (of any size) should be about the inverse square root of the threshold (expressed in fractional terms, not percent). The models fits a range of established countries quite well.
At 4%, that means five parties.
The problem is that Israel already has far “too many” parties for its existing threshold. At 2%, the country “should have” seven parties. In the most recent election, twelve parties (or, rather, lists) won seats. That’s about one and two thirds more than expected. So maybe raising the threshold to 4% would reduce the number of parties in the Knesset to about eight. Coincidentally (or maybe not), that would be a reduction by precisely the number of parties that won more than 2%, but less than 4%, of the vote in the most recent election.