Investments in human capital are individual and collective choices carrying significant external effects. Educated parents and friends accelerate our own human capital accumulation. Skilled colleagues at work increase our own productivity. Sharing experiences with cultured people is gratifying by itself.

We introduce human capital externalities in a stylized model à la Uzawa (1965) and we find that growth can be no longer balanced and the equilibrium can be globally indeterminate.

Labor supply goes to one and capital reaches an upper ceiling in a finite lapse of time above the initial critical value of labor supply ensuring the balanced growth path.

Under a constant tax rate, the government should set a positive rate to speed up human capital accumulation during transition to the capital ceiling.

人力资本投资是具有重大外部影响的个人和集体选择。受过教育的父母和朋友加快了我们自己的人力资本积累。熟练的同事可以提高我们自己的生产力。与有文化的人分享经验本身就是令人满意的。

我们在Uzawa（1965）的程式化模型中引入了人力资本的外部性，我们发现增长不再是平衡的，而且平衡在全球范围内是不确定的。

在超过劳动力供给的初始临界值的有限时间内，劳动力供给达到一个上限，资本达到上限，从而确保了均衡的增长路径。

在恒定税率下，政府应设定一个正税率，以加快向资本上限过渡期间的人力资本积累。