compared to

最近閱讀範例作文時看到這個句子

"The least amount of money was spent on perfume in the UK compared to cameras in France"

過去我一直將這個"compared to xxxxx" 直接視為副詞.


但查了字典後發現"compare"為動詞(或名詞)而字典中也有一個類似的例句
"My own problems seem insignificant compared with other people's."


問題:
1. 如果 "compare"是動詞, 那是不是應該有個被省略掉的關係代名詞?

2.如果有被省略掉的關係代名詞, 那先行詞是什麼? 是" perfume in the UK " 嗎?