We use the seminal transboundary pollution game model in Dockner and Long (1993) and Van derPloeg and de Zeeuw (1992). In contrast with Van der Ploeg and de Zeeuw (1992) and Jørgensen andZaccour (2001), we have taken the ratio of emissions to output as exogenously given. This capturessituations where a cleaner technology is readily available in the more advanced country. Van der Ploegand de Zeeuw (1992) (Section 8) and Jørgensen and Zaccour (2001) consider the case where the ratioof emissions to output is endogenous and is a decreasing function of the level of the stock of cleantechnology. While Van der Ploeg and de Zeeuw (1992) assume that the stock of clean technology ispublic knowledge, Jørgensen and Zaccour (2001) consider the case where the stock of clean technology,also referred to as the stock of abatement capital, is country specific. Each country can invest in theabatement capital in addition to its control of emissions.4We have opted to consider exogenously