Indeed, but not that more expensive. Despite costing in the same range (€6,875/month vs. €6,000/month), the Swiss employee is probably making about €4,500 to €

Indeed, but not that more expensive. Despite costing in the same range (€6,875/month vs. €6,000/month), the Swiss employee is probably making about €4,500 to €5,000 net, while the French one is making €2,300 net. Cost of living in Paris (from your source) are about 30% lower than those in Zurich, so let's divide the French income by 0.7, then we get: Swiss employee: €4,700/month net PPP French employee: €3,285/month net PPP So the Swiss employee is making on average, in this calculation, 45% more money for the same work, using GP's numbers.