Bayview Company, a diverse manufacturer of various goods, transitioned its inventory accounting approach from FIFO to LIFO. This decision was based on the determination that the LIFO method was more advantageous.

Furthermore, Bayview also modified the residual values utilized in the calculation of depreciation for its office equipment. This alteration was implemented effective January $1,2020,$ following the acquisition of supplementary information.

As of December $31,2020,$ Bayview undertook a change in the specific subsidiaries encompassed within the group of companies for which consolidated financial statements are presented.

What type of accounting change characterizes each of the aforementioned three scenarios? For each situation, specify whether the company should demonstrate:

application of a new accounting principle with a retrospective effect

impacts on the financial statements of both the present and upcoming periods

Restatement of the financial statements for all previous periods.

What is the reason for the company's obligation to disclose a change in accounting principle?