The new chairman of the Independent Parliamentary Standards Authority, the body that will regulate MPs’ allowances in future, is everything that you might want in the holder of such an office. Sir Ian Kennedy is respected widely, both wordly and intellectually able and has thought deeply about ethics and the conduct of public office. A person of this calibre is, therefore, worth the £700 daily fee that he will be paid.

Yet his salary, more than twice the daily rate of an MP, certainly raises an interesting question. Why is he being paid this amount? Because it was deemed necessary in order to hire a person of appropriate calibre. In other words, in selecting senior public servants, the relationship between pay and conditions and the quality of the people recruited is recognised as important.

Not, it seems, in hiring MPs. Yesterday’s report by the Committee on Standards in Public Life was prefaced by a list of principles (selflessness, integrity, objectivity, accountability, openness, honesty, leadership) that guided their proposals for MPs’ allowances and staffing. Ensuring that the conditions of office attract and retain people of high professional standing did not feature. It was a revealing omission.

Naturally, no one would wish to have a Parliament full of members whose only interest is money. In any case, one would have to question the intelligence of someone choosing British politics as their route to riches. Yet it is excessively naive to believe that pay and conditions have no impact on the decision to stand for Parliament.

The central features of the new system designed by Sir Christopher Kelly — that MPs will be given far smaller accommodation allowances and only for a rented property, and that many MPs will not even receive these — will have an incentive effect that even an A-level economics student would realise.

The proportion of MPs from wealthy backgrounds will rise, the proportion capable of holding down serious professional jobs but without family wealth will fall. The proportion of those with spouses holding serious professional jobs will decline too. Some MPs will spend more time in their constituency and neglect their parliamentary role, others will spend more time in Westminster and neglect their constituencies. Not one of these is a desirable change.

It was not, of course, Sir Christopher’s fault that MPs’ pay is being determined separately from their conditions. Nevertheless he approved of this separation and ought not to have done. If the issues had been taken together, a simpler and more attractive package might have emerged.

Not everything in the report deserves to be criticised. Issues relating to ethics and accountability are surely handled. Sir Christopher’s system would be far more transparent and far less open to fraud. He is also certainly correct to outlaw the employment of family members — a very dubious practice for public servants to engage in.

Yet the issue is not how to get cheaper politics; it is how to get better politics. Polls show that while almost everyone approves of reducing MPs’ allowances, almost nobody believes that doing so will improve Parliament. And they are correct. Believing that Britain’s political difficulties will be much reduced by the better treatment of mortgages or kettles as an expense is delusional. Sadly Sir Christopher shares this delusion.