In the United States, the Covid-19 pandemic has highlighted glaring social inequality. Many workers cannot afford to be confined to their homes because they are not eligible for unemployment benefit and have not been able to put money aside. Those who have to go to work must find their own face masks. A Covid-19 test costs $150, while being hospitalised with the disease costs $70,000 on average. For the millions of Americans without health insurance, these amounts are beyond their means. Our correspondents report from California.