A mortgage quote helps explain why four central banks can move differently and why their decisions are only part of the story By Dr Laurin Lilly-Laona Friedrich The Bank of England leaves its rate unchanged. A household opening a mortgage renewal quote may still find that its budget is about to change. On 17 September, the Bank held Bank Rate at 3.75%, by six votes to three. Yet quoted two-year fixed mortgage rates were already around 0.95 percentage points above their level before the Middle East conflict. That describes the price of a new deal; each borrower’s experience depends on the deal they are leaving and when it ends. The following day, the Bank of Japan voted seven to two to raise its short-term policy rate from around 1% to around 1.25%, effective 24 September. It nevertheless judged that financial conditions would remain accommodative. An unchanged rate alongside tighter borrowing conditions. A higher rate alongside continuing support. Both make sense once we follow the ann

Dr. Laurin Lilly-Laona Friedrich For a long time, artificial intelligence was relatively easy to imagine as something essentially digital: models, algorithms and software operating somewhere behind a screen. Even as its capabilities expanded, the language surrounding it remained strangely weightless. We talked about data, compute and intelligence as though they existed somewhere separate from the physical economy. That separation is becoming harder to sustain. AI needs data centres, semiconductors, electricity, cooling, grids, land and specialised supply chains. Building and operating that infrastructure requires increasingly large amounts of capital. AI may still appear to us through a screen, but its expansion now has physical, environmental and financial consequences far beyond it. What makes this particularly interesting is that, at almost exactly the same moment, finance is beginning to look towards AI as a way of understanding those kinds of consequences. Consider something like