The purpose of this part 2 is to implement the provisions of section 18 (2)(a) and (2)(b) of article XIV of the state constitution, adopted at the 1970 general election, and the amendment to section 2 of article XI of the state constitution, adopted at the 1974 general election, by permitting and encouraging governments to make the most efficient and effective use of their powers and responsibilities by cooperating and contracting with other governments, and to this end this part 2 shall be liberally construed.