コスト効率[kosutokouritsu] cost effectiveness
圧電効果[atsudenkouka] piezoelectric effect
偉効[ikou] great effect
逆効果[gyakukouka] backfire
経済効果[keizaikouka] (positive) economic effect

効果[kouka] effect
効果音[koukaon] sound effect
効果的[koukateki] effective
効果覿面[koukatekimen] bring an immediate result on