There's a link between two of the biggest political stories of the last few days: David Davis' admission that he hasn't yet done a calculation of the costs of the UK leaving the EU without a trade deal; and George Osborne's getting a £200,000 a year payoff from a Russian oligarch. Both pose the question of how better to incentivize politicians to act in the public interest.

What I mean is that Davis's failure to do basic due diligence probably owes more to him pursuing his private interest - a desire not to hear evidence that discorroborates his beliefs - than to the national interest. And whilst Osborne's career as Chancellor was an abject failure - he wanted to clear the deficit and keep the UK in the EU, failed in both and the two failures are related - he has not suffered financially as a result. Quite the opposite. These are not isolated examples. Brexiters polluted the public realm with lies and racism and suffered no sanction for doing so.

Hence the question: can we better incentivize politicians by ensuring that they suffer penalties for incompetence and dishonesty?

The standard answer here is that elections do this: liars and idiots should suffer a loss of office. This sanction, though, is insufficient. Brexiters gained from their lies, Osborne has profited from being sacked. And the main losers from Labour's defeat in the 2010 election were not so much Labour ministers as workers who have suffered pay freezes and benefit recipients who have been hounded to death.

Nor, of course, do the media discipline politicians adequately. This isn't just because of partisan bias. It's also because of their hideously warped priorities. Hammond's "U turn" on raising NICs has been variously described as embarrassing, humiliating and a disaster. And yet it seems to me to be just what policy-makers should do: swiftly correct what is (only arguably) a mistake before it does real damage. What Hammond should be castigated for instead is pursuing continued austerity in the face of weak expected growth. Yet he gets a free pass here.

I'll grant that there's truth in the old cliché that politicians are motivated by a sense of public service; intrinsic motivations do matter. But can we ensure that extrinsic motivations buttress these?

Frankly, I don't see how institutional tweaks could greatly improve things. Banning ministers from taking jobs after leaving office would risk deterring competent and younger people from politics. And making them personally liable for bad policy would raise tricky problems of distinguishing between bad luck and bad judgment, would run into Campbell's law, and would disincentivize radical policies, as ministers would prefer to fail conventionally.

Instead, perhaps we should just recognize that our problem here is exacerbated by two forces.

One is tribalism. We give a free pass to incompetent or dishonest politicians as long as they're in our tribe. Brexiters aren't slating Davis for his lack of due diligence, just as lefties overlook Corbyn's personal incompetence and laziness.

The other is capitalism. High inequality means there's big money to be made outside parliament for a privileged few. And the desire of financiers, businessmen and oligarchs to ensure that politicians do their bidding means they'll be happy to pay such money. Lebedev and BlackRock aren't paying Osborne for his talents, which are scant, but rather to show current and future politicians around the world what riches are available to them if they play nicely.

This poses the questions. Is it possible to remove the influence of money from politics and thus shore up politicians' sense of public spirit? Given the distorting impact of the media and cognitive biases and errors among voters, would there even be a great gain from doing so? Or might it be that our actually-existing capitalist democracy militates against honest competent politics? Never mind the personal failings of men like Osborne and Davis. The issue here is the very structure of politics.