What does the uniformity of brick size and other artefacts suggest about the state and society in the Harappan civilization?

Existence of centralized authority to control constructions in Harappa. Thereby pointing out the presence of the State.

Archeologists argue that there was a single state, given the the similarity in artefacts, the evidence for planned settlements, the standardised ratio of brick size, and the establishment of settlements near sources of raw material. As of now, the last theory seems the most plausible, as it is unlikely that entire communities could have collectively made and implemented such complex decisions.