SPEAKER_1: Last time we landed on this idea that sovereignty is a strategic asset with a cost of carry — the UK gained regulatory independence but immediately started paying a friction bill. Now I want to pull on the economic thread underneath that, because the trade story sits on top of something deeper. SPEAKER_2: Right, and that deeper thing is productivity. Or more precisely, the collapse of productivity growth. Before 2008, UK output per hour was growing at around 2.1% a year. After the financial crisis, that fell to about 0.6% on average. That gap sounds small, but compounded over a decade, it is enormous. SPEAKER_1: How enormous are we talking? SPEAKER_2: The Office for Budget Responsibility estimates UK output has remained around 14% below its pre-crisis trend path. And by the end of 2016, the shortfall in output per hour specifically was nearly 20% below where the trend line said it should be. Economists call this the UK productivity puzzle — actual performance versus what the trajectory predicted. SPEAKER_1: So not just slower growth — a genuine divergence from where the economy was supposed to be. SPEAKER_2: Exactly. And the UK's divergence was more severe than most other advanced economies. A useful comparison: between 2000 and 2008, UK labour productivity growth averaged roughly 1.8%, close to the US at about 2.1%. After the crisis, the US held around 1% growth. The UK dropped to about 0.5%. That gap compounds fast. SPEAKER_1: So what actually caused the drop? Because a financial crisis hits everyone, but not everyone fell this far. SPEAKER_2: Two mechanisms, and they reinforce each other. Capital deepening slowed — that means slower growth in the capital available per hour worked. Second, multifactor productivity — the efficiency with which you combine all your inputs — also weakened. The Bank of England found that most of the post-crisis weakness happened within firms, not because workers moved to worse industries. SPEAKER_1: Wait — within firms, not between industries? SPEAKER_2: Correct. And that matters because it rules out a simple structural story. It is not that Britain shifted workers into low-productivity sectors. The problem is that firms across sectors stopped getting more efficient. One Bank of England study estimated that reduced resource reallocation — capital and labour not moving to their best use — explained around one-third of the slowdown. SPEAKER_1: And investment is the link, right? Because if firms are not investing, they are not getting more efficient. SPEAKER_2: That is the core mechanism. The UK has had the lowest investment share of GDP among G7 countries in 24 of the last 30 years covered by government analysis. It routinely ranks in the bottom 10% of OECD countries for overall investment intensity. A 2024 OECD assessment confirmed that years of low business investment had directly contributed to sluggish productivity growth. SPEAKER_1: [sigh] And then 2016 arrives and the referendum result lands. What did that do to investment decisions? SPEAKER_2: It introduced what you might call a Policy Certainty problem. Firms making decisions about machinery, software, or a new facility need a 10-year horizon. The referendum created genuine uncertainty about regulatory frameworks, trade access, and labour supply — all at once. When the future rulebook is unclear, the rational response is to wait. And waiting means the capital deepening that drives productivity simply does not happen. SPEAKER_1: So what our listener might be wondering is: if employment stayed high, why does any of this matter? Record-low unemployment sounds like good news. SPEAKER_2: This is the Substitution Error — and it is a real trap. High employment and high productivity are not the same thing. For example, suppose a firm hires three people to do work that one well-equipped worker could handle. Employment goes up. Output per hour goes down. The UK ran close to that pattern — lots of people in work, but in roles with limited capital behind them, limited skills investment, limited efficiency gains. SPEAKER_1: So record-low unemployment can coexist with weak public finances and stagnant living standards. SPEAKER_2: Precisely. And the OECD identified where the shortfall is concentrated: non-financial services account for roughly half the productivity gap, financial services for about a quarter, with manufacturing and construction making up the rest. The problem is broad, not confined to one sector. SPEAKER_1: The takeaway, then — what does fixing this actually require? SPEAKER_2: [short pause] Policy certainty, sustained over a decade. Firms invest in machinery, software, skills, and infrastructure when they trust the rules will not shift under them. The UK's challenge is that it has cycled through multiple fiscal frameworks, regulatory pivots, and political disruptions in a short window. Remember: a sources-of-growth analysis found that by 2019, UK labour productivity was roughly 31% below where it would have been had pre-2007 growth continued. That is the cost of the stagnation trap — and closing it requires stability as much as any single policy.