Taipei mayor Chiang Wan-an is under fire after his son won a city-funded exchange-student place, and his aide's defense has made the criticism worse rather than better.

• The mayor's son passed the city education department's selection and will spend a year studying in the US and Canada on a city scholarship.
• Critics say the mayor never stepped aside from a program his own administration changed during his term.
• A key rule said students who fail to get a visa lose the place and repay the money, but the city's defense recast it as a rule about nationality instead.
• The defense that "it has always been done this way" and that three or four other winners also hold dual citizenship reads as admitting the practice, not excusing it.
• Few Taipei middle schoolers hold dual citizenship, so a high share of them among just 25 winners raises questions about who the selection really favors.

Outlook: Pressure will likely grow on Taipei's city government to explain how the 25 places were awarded and whether the rules were bent.