Abstract: This paper extends symmetrical duopoly real option timing game model under uncertainty by introducing a time-to-build,analyzes the influence of time-to-build on firms' investment decision and investment cascades.As the time-to-build increasing,the payoffs of firm's decrease and investment thresholds increase,so firms prefer waiting to investing even facing the threat of preemption of the rival.The further analysis shows that the greater demand market volatility will be the one more prone to investment cascades,and unlike economic intuition,time-to-build has no effect on investment cascades as well as investment cost.In addition,the model provides an explanation for the local over-investment phenomenon in an industry.

Key words: real options, option game, investment decision equilibriums, time-to-build, investment cascades