The Paris School of Economics sits on the drab grounds of what was once the école Normale Superieure for girls, tucked away on the city’s unspectacular bottom edge. The PSE was only founded in 2006. It only teaches graduate students. It can’t match Harvard’s $53bn endowment. Yet it’s a remarkably influential place.

The school’s president, Esther Duflo, is a Nobel laureate in economics recently returned to her hometown from Harvard. The PSE’s co-founder, Thomas Piketty, did more than anyone else to put inequality on his profession’s agenda. Two decades ago, he also supervised the masters thesis of the school’s current star, Gabriel Zucman, on whether high taxes prompt rich people to emigrate. Today Zucman, a boyish-looking 38, winner of the John Bates Clark Medal for young economists that often precedes a Nobel, is leading a drive to impose a global wealth tax on the super-rich.

The EU Tax Observatory, which Zucman runs, hosted a conference in April at the PSE for the small but global community that has clustered around this tax. Besides economists, there were delegates from the IMF, the Brazilian government, Belgium’s workers’ party and an OECD official attending in her private capacity as a “tax nerd”. PSE’s more profit-maximising students snuck in for free helpings of the Parisian-quality lunch buffet. The message of the conference: the super-rich pay lower tax rates than ordinary people, but Zucman and his followers intend to change that.