To wangle £11bn ($14bn) out of the British government, it helps to write a blog post. “Full expensing”, which allows firms immediately to write off their spending on machinery, plant and computer equipment from their taxable profits, was the costliest part of Jeremy Hunt’s autumn statement on November 22nd. A long-standing policy in America, the idea of full expensing first wormed its way into British politics in 2017 via blog posts from Sam Dumitriu and Sam Bowman, both then of the Adam Smith Institute, a small think-tank known for its staunch neoliberalism and deranged internet memes about its Scottish namesake.

A post can easily become policy. In a crisis, wrote Milton Friedman, “the actions that are taken depend on the ideas that are lying around.” Thanks to the tweets and blog posts of a few centre-right types, full expensing was lying around when the government propped up the economy during the pandemic. A souped-up version of full expensing was first introduced on a temporary basis by Rishi Sunak, the then-chancellor; Mr Hunt has made the policy permanent. A few blog posts helped overhaul the tax regime.

In Britain this posting-to-policy pipeline—when online writing becomes government policy—is in full flow. The usual plumbing of policymaking is showing its age. What once took reams of little-read 80-page reports, interminable roundtables and hundreds of thousands of pounds can now be achieved with a few blogs and incessant tweeting. The sharpest wonks are constantly online; the fastest way to lobby a minister, present or future, runs through X (formerly Twitter). For a snapshot of what Britons think, self-selecting online weirdos who talk about politics all day are a terrible guide; for a peek at what the government will eventually do, there is no better place to look.

Full expensing was worth billions and took four years to go from post to policy. Smaller victories are possible much faster. Over the summer Mr Sunak, the prime minister of a nuclear power, took the time to ban a specific breed of dog called the XL Bully. It “is a danger to our communities”, said Mr Sunak, in a video recorded especially. He did so largely because of a blog by Lawrence Newport, an academic at Royal Holloway, University of London, which linked the rise in popularity of the XL Bully with an increase in fatal dog attacks. Dr Newport and a few other volunteers produced idiot-proof guides on how to ban them. Journalists were spoon-fed stats. Posters posted. The results were speedy. Dr Newport’s post, which sparked the coverage, came out on June 6th; by September 15th Mr Sunak was addressing the nation. A post had become policy in barely 14 weeks.

Posting influences oppositions as well as governments. Yimbyism, once a niche idea reserved for a few very-online activists, has taken over the Labour Party. Sir Keir Starmer, the Labour leader, insists he is a builder, not a blocker. It is a bold move. In a constituency-based system, the diffuse benefits of building often come second to the concentrated inconvenience of development. Even if his specific plans are unclear, talking-points lifted straight from the posts of yimby activists now litter Sir Keir’s speeches (did you know the planning application for a tunnel under the Thames is 30 times longer than the entire works of Shakespeare?). yimby versus nimby is now a key dividing-line at the next election.

Posting has its limits. Tom Forth, a blogger, is one of Britain’s most influential wonks, largely owing to his part-time posting (which he does alongside his job at the Data City, an ai startup in Leeds). Mr Forth’s criticisms—that the government spends far less on research and development in northern England and the Midlands than the private sector does, and that Britain’s second-tier cities are held back by lousy public transport—are now the norm in policyland. Neil O’Brien, a former Tory minister, says Mr Forth’s output “heavily shaped” the government’s work on industrial strategy and “levelling up”. Both Theresa May and Boris Johnson pledged to fix the problems Mr Forth identified. Neither succeeded. Posting can easily change government policy. But that does not mean government policy can easily change Britain.

The efficiency of the posting-to-policy pipeline has its drawbacks, too. Good ideas, like full expensing, are usually nicked from across the Atlantic, points out Mr Dumitriu, who now works at Britain Remade, a pro-growth lobby group. But bad ideas can make the leap, too. Suella Braverman’s war on homeless people using tents is a chronic example. The former home secretary saw a problem that is genuinely bedevilling San Francisco and imagined it was happening in Surbiton. “When you gaze for long into the abyss, the abyss gazes also into you,“ wrote Nietzsche.  The same applies to a Twitter timeline.

Judged not by the content of character, but their content

Posting alone changes nothing. A few posts may have triggered interest in full expensing but it still took plenty of meetings and arguments to win over those in government. The Centre for Policy Studies, a storied Tory think-tank, noisily praised the policy (as did The Economist). The posting-to-policy pipeline tends to benefit those with a modest profile already, whether academics, former think-tankers or well-established analysts. Likewise, those who are most capable of harvesting attention are best-placed to boost their policies. Attention can be gained in many ways: Mr Bowman mixes analysis of tax policy with amusingly implausible boasts, such as insisting he is the inventor of the tomato salad.

Yet for all its idiosyncrasies and flaws, the posting-to-policy pipeline is to be welcomed. The more good ideas there are lying around, in Friedman’s phrase, the more chance there is of a good one being picked up in government. Voters may not spend much time scrolling through tweets or reading Substack newsletters. But bored ministers, their aides, stuck-for-ideas civil servants, journalists and wonks certainly do. Posting is not the real world; it is much more important than that. ■

Read more from Bagehot, our columnist on British politics:
What kind of legacy does Rishi Sunak want to leave behind? (Nov 23rd)
What David Cameron’s return says about British politics  (Nov 13th)
To understand Britain, watch “Homes Under the Hammer” (Nov 9th)

Also: How the Bagehot column got its name