Coalitions have advantages of greater representation and restraining the government from changing policy suddenly and randomly, permitting policy stability. It helps to fuse the regional aspiration with the national government thereby diluting the sub-regionalism.
It prevent authoritarianism of a single majority party rule. It can prevent the undue constitutional crisis like emergency.
It helps to make parliament function better and the parliamentary control over the executive also increases. It increases the accountability of executives.
Coalitions forced parties involved to arrive at common minimum Programme. The objectives of the CMP will help to judge the work of the coalition government better.
Our experience with the coalition and the pre coalition era shows that our macroeconomic indicators averaged out were better in coalition era as compared to pre coalition era. Example Economic reforms during minority govt. in 1991. Hence having majority in the house does not guarantee good governance.