I've been thinking about the question I posed yesterday: why don't politicians trying to convince the public on the need to cut spending cut some of their own salary or allowances to win hearts and minds?
And I think I know the answer.
In a parliamentary system one of the hardest jobs the leaders have is to rally, control and maintain unity among their MPs. These may include members who've worked very hard to win marginal seats, members on the back bench not earning big bucks, members already getting disillusioned or embittered and members on the rise looking for any excuse to either jump ship or try and take your job.
Most governments try and do the cost-cutting early in their term, aiming to get the pain - and public anger - out of the way early and betting that the electorate will have forgiven and moved on by the time of the next election.
So the most important hearts and minds the leaders need to win during this sort of program are those of their own MPs.
And of course, from a purely budgetary standpoint, cutting MP allowances won't deliver the same millions or billions beckoning them temptingly from the list of public benefits and subsidies, so they probably don't see it as worth the pain, considering the factors above. To sell a belt-tightening program and help you through all the hard work of your pet reforms, you need your MPs on-side and energetic, not bitter and angry.