経済 けいざい せい向上 こうじょうじゃなかったです
keizai sei kōjōjanakattadesu

Noun
Desu Copula

The polite, past negative form of 経済性向上

1. It wasn't about improving economic efficiency.; It wasn't about cost-effectiveness.

Past/Perfective
Negative
Polite
Casual Register