Song, J. 2019. Coastal city infrastructure investment forecast based on gray system theory. In: Gong, D.; Zhu, H., and Liu, R. (eds.), Selected Topics in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 94, pp. 629–633. Coconut Creek (Florida), ISSN 0749-0208.

In the context of the increasing gap in infrastructure construction between developed and undeveloped areas of coastal cities, the practical of investment and financing projects, especially investment and financing of infrastructure construction in economically undeveloped areas of coastal city, are important issues to be solved urgently. Moreover, the use of forecast will be conducive to investment and financing decisions. This paper proposed a gray GM (1, 1) model based on gray system theory, and used the panel data of coastal city infrastructure investment from 2010 to 2014, to forecast the amount of investment in Guangzhou from 2015 to 2018. The forecast results show that the gray system theory has high accuracy in forecasting urban and rural infrastructure investment and can provide decision support for managers.