The Separability of Production and Location Decisions: Comment
评论了Hurter等人的观点，指出只有当生产函数为固定比例类型时，成本最小化企业的选址决策才能与投入组合决策分离，而齐次性既非必要也非充分条件。
In a recent note in this Review, Arthur Hurter, Joseph Martinich, and Enrique Venta (hereafter Hurter et al.) consider the question of the conditions under which the location decision for a cost-minimizing firm can be treated separately from the decision governing the firm's desired input mix. The authors argue that if the firm's production function is homothetic, total costs can be minimized by first determining an optimal location for the facility, and then determining the optimal input mix at this location. The implication of this viewpoint is that facility location and facility design problems can be analyzed independently. Thus the traditional theory of the firms which abstracts from spatial elements, and the traditional Weberian theory of industrial location which does not consider the choice of input mix, remain independently valid without involving the possibility of suboptimal decision making on the part of the firm. My purpose here is to clarify the conditions under which this type of separability does obtain: in particular, I argue that the facility location problem can be solved independently of the input mix selection problem if and only if a firm's production function is of the fixed proportions type. This implies that homotheticity is neither necessary nor sufficient for separability of these decision problems.