Missing Values Missing values may occur because of non-reporting or non-availability of data. SHAZAM has the capability to recognize missing values and delete these from estimation procedures. The requirements for working with missing values are: A SHAZAM missing value code must be set. The default value is -99999. However, another value can be set with the SET MISSVALU= command. For example, to set a missing value code of -123 the command to enter is: SET MISSVALU=-123 The missing value code should be chosen so that it does not match a number that may naturally occur. For example, a missing value code of 0 is not a good idea since 0 may be an acceptable value for a variable. The SET SKIPMISS command must be used. This tells SHAZAM to turn on automatic deletion of missing values for data analysis. Warning For time series methods (for example, the estimation of ARIMA and ARCH models) the deletion of missing values may not be desirable. [SHAZAM Guide home]