When the authors eliminated the time delays in the model, the demand amplification was significantly reduced.
This result led to the argument that both material and information delays would be possible causes of the bullwhip effect.
Along with this, they argued that the removal of one or more intermediaries led to the significant reduction of the bullwhip effect.
This argument was also reinforced by Ackere et al. (1993) and Hong-Minh et al.(2000).