Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four-fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past.

　　than 既可以当连词(conj.)引导状语从句又可以当介词(prep.)作状语：

　　1. I am older than Lisa.

　　than为连词 = I am older than Lisa (is).

　　2. I am older than her.

　　than 为介词，后方跟宾格her

　　than 引导句子时后方有时需倒装

　　参考译文

　　然而，有充分的理由预计，目前的经济后果不会像上世纪70年代那么严重。与上世纪70年代相比，现在大多数国家的原油成本在汽油价格中所占的比例要小一些。在欧洲，税收占汽油零售价的比例高达五分之四，因此，即使原油价格相当大的变化(原油价格发生相当大的变化)，对零售价格的影响也比过去要小得多。