Structural Change and Big Data

Recall the tall-wide-dense (T, K, m) Big Data taxonomy.  One might naively assert that tall data (big time dimension, T) are not really a part of the Big Data phenomenon, insofar as T has not started growing more quickly in recent years.  But a more sophisticated perspective on the "size" of T is whether it is big enough to make structural change a potentially serious concern.  And structural change is a serious concern, routinely, in time-series econometrics.  Hence structural change, in a sense, produces Big Data through the T channel.