I know this is hardly the most pressing problem at the moment, but with talk of John Bercow finally taking his leave, the point has occurred to me again: why do we allow the balance of power in the Scottish Parliament to be artificially affected by the choice of Presiding Officer? At Westminster, the Speaker and all three Deputy Speakers do not usually take part in votes, which means that two MPs can be selected from the government side and two MPs from the opposition, thus maintaining the balance of power that people voted for (or, more accurately, that the election produced). But at Holyrood only the Presiding Officer him/herself is barred from voting, meaning that the government's numerical position is inevitably either slightly strengthened or slightly weakened.
This of course ensures that the choice of Presiding Officer is not just influenced by the merits of the individual but also by the tightness or otherwise of the parliamentary arithmetic. The SNP could 'afford' to install one of their own in the role after winning an outright majority in 2011, but were suddenly happy enough to agree that it was Labour's 'turn' after slipping back into a minority in 2016. And in 2007, when the SNP won 47 seats and Labour won 46, it was inconceivable that the Presiding Officer would be drawn from anywhere but the ranks of the smaller parties.
So it's an unsatifactory system in more ways than one. I can see a few potential solutions:
1) The simplest is to replicate the Westminster convention. Have a Presiding Officer 'team' that is made up of an even number of MSPs, and bar them all from voting. However, this arguably means that a greater number of voters are not being fully represented in parliament.
2) Replace the Presiding Officer with a new voting MSP as soon as they are selected. This is simple enough if the new PO is a list member, because they can simply be replaced by the next person on their own party's list. But if they're a constituency member, there would need to be a by-election, which some people might find a bit needless so soon after a full election.
3) Allow MSPs to elect a Presiding Officer from outwith their own ranks. This seems totally unthinkable until you stop to question why it's so unthinkable. Why would a suitable non-MSP do the job any less conscientiously than an MSP? That person would have their own mandate (albeit an indirect one) and would naturally be expected to swear the same oath and uphold the same standards as any elected MSP.