I disagree with Joan Martínez Alier’s view that Catalonia’s research funding could increase if the region were to become independent of Spain (Nature 576, 384; 2019). For a start, Catalonia would lose out on future European research grants because it would cease to be a member of the European Union. And, contrary to Alier’s suggestion, discontinuing fiscal transfers to Spain would make little difference in its landscape of bulging public debt, departing businesses, and no access to European Central Bank financing.

Madrid has a comparable weight in Spain’s economy. Although fiscal transfers from Madrid to the rest of Spain are much higher than those from Catalonia, its absolute and per capita public debt are less than half those of Catalonia. Since 2012, Catalonia has drawn more than €70 billion (US$78 billion) in favourable-term loans from Spanish public sources such as the Regional Liquidity Fund. To make matters worse, an independent Catalonia might need to add its share of Spanish public debt — around another €200 billion — to its regional debt (see go.nature.com/37kqc1c).