關(guān)于本文標(biāo)題所列兩詞之異同，請先看出版者自詡為“準(zhǔn)確， 完備”的《英漢大詞典》:
1. (a) estate tax（美）= estate duty
    (b) inheritance tax（美）遺產(chǎn)稅，繼承稅
    (c) estate duty（英）房地產(chǎn)遺產(chǎn)稅
如此說來，那末至少從美國英語來說（這樣可以注意更集中， 問題可以更清楚），”estate tax”指“房地產(chǎn)遺產(chǎn)稅”而“inheritance tax”則是一般地指“遺產(chǎn)稅，繼承稅”的了。
詞態(tài)果真如此嗎？不！
關(guān)鍵首先在于”estate”果真就指“房地產(chǎn)”嗎？回答是否定的。 請看：
2. estate /. . . / n | a (large) piece of land in the country, usu. with one large house on it and one owner 2 BrE ... 3. law the whole of a person's property, esp. as left after death:... [例句從略] 4..
                                   -- Longman Dictionary of Contemporary English
可見，至少在法律用語（law）中（不問英美）“estate"是指“人(特指其身后所遺）的全部財(cái)產(chǎn)”。因此，在這一意義上縮小為“房地產(chǎn)”是缺乏根據(jù)的。不過，我們不能以此為滿足，而必須進(jìn)一步證明--“estate tax”中的“tax”并不以不動(dòng)產(chǎn)即房地產(chǎn)為限：
3. Estate tax
                        —《英米法辭典》（日本有斐閣版）
日語只是消極地證明了“estate tax”與“ inheritance tax”兩語之間不存在其為動(dòng)產(chǎn)抑或不動(dòng)產(chǎn)的區(qū)別。此后，還要證明究竟存在不存在以及存在什么區(qū)別。請看：
4. ESTATE TAX tax upon the transfer of property, and not a tax on the property itself. Estate taxes are based on the power to transmit or ihe transmission from the dead to the living, while inheritance taxes are based on the right to receive the property and are thus applied to the recipients thereof.
                                        ——Steven H. Gifis, Law Dictionary
由此可見，兩者之區(qū)別在于如表: