Reacting to the Israeli election result, Patrick Hennessy plays out a scenario in which Britain adopted the Israeli electoral system. He suggests it would all end badly and that the Tories should remain resolutely opposed to modifying our election system. That's fine. But the Israeli situation no more demonstrates the failures of PR than our own lop-sided system demonstrates the inadequacies of a first-past-the-post system. That is to say, it both does and doesn't. There's no perfect*, universally fair and clear electoral system. If there were then someone might have found it by now. As Matt Yglesias says, different countries suit or require different systems.
Hennessy claims that the PR system used in the Scottish parliament has not led to demonstrably better government. And that's true to an extent. But only an extent. Using first past the post would have ensured a pretty much impregnable and permanent Labour majority. (Of course, agreeing to PR was a necessary concession for there even to be a Scottish parliament).
And it's not as though first-past-the-post, whatever its merits in terms of clarity and direct representation, is perfect: Labour only won 35% of the vote at the last election yet ended with 356 seats. The Tories took 32% and won just 198 seats. That produced a clear result, for sure, but hardly one that accurately represented the collective will of the people.
*Possible exception? Belgium! After all, a system which leaves the country pottering along without any government at all can't be all bad and might, in fact, be rather better than most...