24 September 2026
The OECD’s latest Interim Economic Outlook presents a global economy that has proved more resilient than expected, but where growth is increasingly supported by a relatively narrow set of factors. Global GDP growth is projected at 2.9% in 2026 and 3.0% in 2027, although momentum slowed from an annualised 3.6% in the second half of 2025 to 2.6% in the first half of 2026. The OECD identifies continued strength in AI-related investment and production as an important offset to weaker momentum elsewhere.
AI-related investment is making a meaningful contribution through spending on data centres, technology equipment, semiconductors, and associated infrastructure. In the US, strong AI investment is expected to partly offset softer consumer spending and weaker real-income growth, while AI-related goods shipments have become an important source of trade growth, particularly across Asia. AI is therefore a genuine near-term growth driver, but its growing contribution also creates a degree of concentration risk.
The sensitivity lies in the scale of investment relative to expected returns. Current spending assumes substantial future earnings and productivity gains. If those returns take longer to materialise, or fall short of expectations, investment could slow and the effects could extend beyond technology. The OECD notes that earnings growth among AI-related companies would need to rise rapidly to support current expectations, while weaker returns could affect associated industries such as engineering and construction, as well as financial markets. This is not a forecast of an AI downturn, but a reminder that part of the current growth impulse ultimately depends on investment translating into tangible economic returns.
The inflation backdrop is also becoming less forgiving. G20 headline inflation is projected to rise from 3.4% in 2025 to 4.1% in 2026, before easing to 3.6% in 2027. More than half of G20 economies currently have inflation above target, with renewed energy and commodity pressures adding to uncertainty. The OECD therefore expects inflation to moderate gradually rather than assuming a rapid return to the low-inflation environment of the previous decade.
Bond markets provide another source of sensitivity. Long-term sovereign yields have risen to their highest levels in 15 years across several major economies, reflecting concerns over fiscal sustainability and substantial borrowing requirements. Higher yields increase debt-servicing costs for governments and raise funding costs for companies and households. The OECD also highlights increased competition for capital from strong bond issuance by AI-related companies, adding another potential pressure on borrowing costs.
The result is a more nuanced picture than the headline growth numbers suggest. The global economy is not being sustained by AI alone, and the OECD’s baseline remains one of continued expansion. However, with inflation still elevated and long-term yields higher, the durability of AI investment and the returns generated have become increasingly relevant to the wider growth and market outlook. If expected productivity and earnings gains take longer to emerge, the adjustment could extend beyond technology, highlighting the importance of looking beneath the headline figures, and interrogating how growth is being sustained.