Before you listen to the programme, look at these comprehension questions: you'll hear the answers during the programme. You can also download this programme in mp3 format and a transcript from the Extras section below.

Money that is earned tax free within a country because the government doesn't know about it. A way for the government to collect money by getting people to pay extra money on goods and services (as opposed to taking a percentage straight out of people's earnings, for example).