生物科技廠商的競賽──農業再發展的關鍵

A Race between Biotech Firms - A Key to the Further Development of Agriculture

A prosperous biotech industry can induce a revolutionary development of agriculture. Patent races are common in biotech and pharmaceutical industries. We have presented two models: one discrete time and the other continuous time, with asymmetric information between two R&D competitors. We have shown for both models the low cost type always expend more effort than the high cost type. For the discrete time model, we find the effort made in period 2 is greater than in period 1 for both types. There is an end effect in period 2, so that effort in this period is higher. As for the continuous time model, we find the end effect still exists and the optimal path of the hit rate won't converge to the steady state. Asymmetric information is the central issue of this paper. We have conjectured that in the continuous time case, the hit rates of the firms are going down as time elapses. The intuition behind this is that as time elapses and a discovery has not yet been made, the firm is going to believe that his opponent is of a weaker type and thus relax himself by reducing his hit rate. However, we obtain the result that the hit rate can be increasing or decreasing, because the end effect exists. When end of game is approaching, the firm will expend all his effort to make the discovery and increase the intensity of his R&D effort. The ultimate result is ambiguous, depending on which effect is predominant. 生物科技的蓬勃進步可以帶動農業的革命性發展。專利權的競賽，在生物科技和製藥產業中是相當普遍的現象。本文在資訊不對稱的情況下，分析二個R&D競賽模型（不連續與連續）。不管是連續或不連續的模型，低成本型態的廠商總是會比高成本型態的廠商努力進行研發。在不連續的模型下，兩種不同型態的廠商在第二期的努力程度會大於第一期，亦即在第二期有所謂的“結束效果”。在連續的模型下，結束效果仍然存在，且最適努力程度的軌跡不會趨近穩定狀態，隨著時間的延續，最適的努力程度可能增加或減少，這個結果與Reinganum[1981,1982]的結果是不同的。