FDI not only increases capital supply in the host country, but can also improve the productivity of domestic firms through knowledge transfer. Dutch diseases and technology spillover can be some of the important effects of FDI in the oil and gas (OIG) sector. The Dutch disease refers to the problems associated with negative consequences of large increases in a country's raw materials such as oil and gas. However, affecting productivity depends on the absorptive capacity or the ability to adapt foreign technology by domestic firms. If Foreign direct investment (FDI) inflow is without productivity spillover, it may have negative effects on economy, especially if the destination of FDI is sectors such as Oil and gas sector(OIG). FDI not only plays a vital role in the development of this sector, but also significantly affects the macro and micro levels. Identifying the type and extent of these effects on economy requires quantitative and empirical evaluations. Therefore, the current research has tried to study the effects of FDI in the OIG sector on Iran's economy using a regional CGE model. The results showed that if FDI does not lead to productivity spillover, it causes Dutch disease in the economy of Iran. Production and employment have decreased in tradable and increased in non-tradable sectors. If FDI improves productivity of the firms, the impacts of Dutch disease will be reduced or eliminated. Therefore, production will be improved in all sectors, and consumer price index will decrease. In this regard, the absorptive capacity of domestic firms plays an important role in the extent of technology spillover and finally reducing the impact of Dutch disease.

外国直接投资不仅增加了东道国的资本供应，而且还可以通过知识转移提高国内公司的生产率。荷兰的疾病和技术外溢可能是外国直接投资在石油和天然气（OIG）领域的一些重要影响。荷兰病是指与石油和天然气等一国原材料大量增加所带来的负面影响相关的问题。但是，影响生产率取决于吸收能力或国内公司适应国外技术的能力。如果外国直接投资（FDI）流入没有生产率溢出效应，则可能对经济产生负面影响，尤其是如果外国直接投资的目的地是石油和天然气部门（OIG）。外国直接投资不仅在该部门的发展中起着至关重要的作用，但也会显着影响宏观和微观水平。确定这些对经济的影响的类型和程度，需要进行定量和经验评估。因此，当前的研究试图使用区域CGE模型研究OIG部门外国直接投资对伊朗经济的影响。结果表明，如果外国直接投资不导致生产率溢出，它将在伊朗经济中引起荷兰疾病。贸易中的生产和就业减少了，非贸易部门中的生产和就业增加了。如果外国直接投资提高了企业的生产率，那么荷兰疾病的影响将减少或消除。因此，所有部门的生产将得到改善，消费物价指数将下降。在这方面，