When the economy is going well, the poor benefit more than others. But when things are going badly, it is the poor who are hurt the most. This is especially true in the case of the Covid-19 pandemic, which has hit poor countries — and the poorest people within them — especially hard. Some poor countries were facing economic difficulties before the pandemic, which intensified their troubles. Others were reasonably well managed, but suddenly faced the need for unanticipated expenditures. International support for this latter group can be highly productive. But for countries that already had big …