$n$ agents simultaneously choose private consumption $x_i$ and public-good contribution $y_i$ to maximise $u_i = x_i\, \Big(\sum_{j=1}^n y_j\Big),$ subject to $x_i + y_i = b$, $x_i, y_i \ge 0$. As $n$ increases, the total Nash equilibrium expenditure on the public good