Abstract: A residual value of goods based on data is forecast based on a secondhand price database storing transaction data including the residual value of objects and age of the objects. A standardized forecast residual value is calculated for a prescribed future time based on the standardized residual value. The standardized residual value is calculated by modifying a residual value of the object included in the transaction data stored in the secondhand price database based on attribute values of a prescribed attribute of the object included in the transaction data. A non-standardized forecast residual value is determined by making adjustments corresponding to the attribute values of the object of which the residual value will be forecast.