The Combination Forecasting Model Based on the Gray System GM(1,1) and its Application in the Economic Fields

Since GDP is one of the most important indicators for the urban or the regional economic development, forecasting the trend of GDP scientifically and accurately is of practical significance. By utilizing the combination forecasting model based on the gray system GM(1,1), an interval is used as the result of the prediction. In this paper it is modeled to the Tianjin's GDP from 1999 to 2005 and from 2003 to 2008 as the original data sequences separately, estimated the values of GDP in 2009 and 2010, then compared with their corresponding original values, and subsequently concluded that our prediction model has a satisfactory level of the accuracy to the Tianjin's GDP from 2003 to 2008 when it is used for the forecast of the short-term GDP trend. Moreover, we conduct forecasting for GDP from 2011 to 2013. Using an interval as the prediction result improved the prediction accuracy and practicality.