This paper considers a one-stage Cournot duopoly of R&D. We characterize the Nash equilibrium of the one-stage game and provide a comparison with the two-stage version of the same Cournot model of R&D/product market competition. We look at R&D expenditures, profits, output and welfare. Under perfect symmetry, the one-stage model always leads to higher profits when the spillover parameter is not equal to 1/2. Moreover, the one-stage model implies more R&D expenditure and higher welfare if and only if the spillover parameter is greater than 1/2. The insights are robust to an n -firm generalization, but the differences between the one-stage game and the two-stage game disappear as the market becomes perfectly competitive.

本文考虑了研发的一阶段古诺双寡头垄断。我们描述了单阶段博弈的纳什均衡，并与研发/产品市场竞争的同一古诺模型的两阶段版本进行了比较。我们关注研发支出、利润、产出和福利。在完全对称的情况下，当溢出参数不等于1/2时，一阶段模型总是会带来更高的利润。此外，当且仅当溢出参数大于 1/2 时，一阶段模型意味着更多的研发支出和更高的福利。这些见解对于n企业的概括来说是稳健的，但随着市场变得完全竞争，一阶段博弈和两阶段博弈之间的差异就会消失。