why would acf output be negative if lag were to increase why does acf output become negative as lag increases why is acf negative when lag increases why acf output becomes negative as lag increases why does the acf output become negative as the lag increases? why does the autocorrelation of the acf output become negative as lag increases? why is the acf output negative as the lag increases why does the acf output become negative as lag increases? why does acf output become negative as lag increases? why does acf output become negative as lag increases? why acf output becomes negative as lag increases? when acf output becomes negative why is the acf output negative when lag increases? why does acf output become negative why does acf output become negative when the lag increases? why does the acf output become negative as lag increases why does the ACF output become negative as lag increases? why is the ACF output negative when lag is negative is the correlation positive. why does lagging output become negative