Kenya's cash ban will be "effective" to formalise the economy: economist Kenya's new bank notes policy will be "effective" in "formalising the economy", Kenyan economist Aly-Khan Satchu says. A new print of the 1,000 shilling banknote, the largest denomination, was rolled out in June, with Kenyans given to September 30 to exchange their old bills at the bank or be stuck with bundles of useless cash. IMAGES AND SOUNDBITES