We reformulate the quality ladder model of Pakes and McGuire, Rand Journal of Economics, 25(4), 555–589 (1994) as a dynamic stochastic game with random moves in which each period one firm is picked at random to make an investment decision. Contrasting this model to the standard version with simultaneous moves illustrates the computational advantages of random moves. In particular, the quality ladder model with random moves avoids the curse of dimensionality in computing firms’ expectations over all possible future states and is therefore orders of magnitude faster to solve than its counterpart with simultaneous moves when there are more than just a few firms. Perhaps unexpectedly, the equilibria of the quality ladder model with random moves are practically indistinguishable from those of the model with simultaneous moves.

中文翻译：

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具有随机动作的动态随机游戏

我们重新制定了Pakes and McGuire的质量阶梯模型，Rand Journal of Economics，25（4），555–589（1994）是具有随机移动的动态随机博弈，在该随机博弈中，每个公司随机选择一个时期来做出投资决策。通过同时移动将该模型与标准版本进行比较，可以说明随机移动的计算优势。尤其是，具有随机移动的质量阶梯模型避免了计算公司对所有可能的未来状态的期望中的维数诅咒，因此，与存在多个公司的同时移动的同行相比，求解速度要快几个数量级。也许出乎意料的是，具有随机运动的质量阶梯模型的平衡实际上与具有同步运动的模型的平衡几乎没有区别。