Game theory explanation of why journalists don't call out lying politicians

There is also the issue of access. A political reporter's career is essentially over if sources won't talk to them. Habitually 'calling out' politicians is a very easy way to become a persona non grata inside the beltway or in Westminster. The risk of losing access is the sword of Damocles hanging over every political journalist.

I'd posit that a large part of the issue with media reporting is that the media has a disincentive to be honest. The way they stay afloat as business entities is through commercial means - either subscribers or advertising or both. That means eyeballs, which means that the business case for sensationalist reporting will always trump that for honest, factual reporting.

The only way to reliably get around this is to have a separate, non-partisan funding mechanism for news. For all it's flaws, it's why the BBC tends to do well. Just being independent isn't enough (see The Independent as an example for that).

Side note, this is partly why the BBC gets a lot of flack for both sides - when they say things that support one position, the other side invariably accuses them of bias. Even they don't get it right all the time though, and never will (being run by humans who, you know, get things wrong).

The best thing America could do for it's political system is outlaw media outlets from reporting news and being for-profit. Instead, set up a slush fund of a few billion to pay for all news, and then ban themselves from interfering except to punish those who are partisan one way or the other.

Reporting should be about educating people as to the state of the world, and local, relevant information. Not entertainment.

Fun fact: in the UK, this trend really started with the publishing of the memoirs of Christine Keeler in the News of the World, which also kicked off the rise of Rupert Murdoch's empire. The scandal that ensued became known as the Profumo affair and by location centred around Cliveden House, which has 400 acres of woodland which include the cottage where I live.