Who is more exposed to a semiconductor supply shock, China or the US? We split out semiconductors in the ICIO tables economists use to trace supply chains and found that China's exposure is about 2.7× that of the US. Our updated tables, which extend work by the OECD, let us model the impact of a major supply-chain shock. We simulate the global economy 2–3 years after a large fall in Taiwanese productivity plus a full China–West trade decoupling. Our simulation shows China's real GNE falling…