Furthermore, he is completely surrounded by banana peels. Canada's economy is slowing down, though less so far than extreme pessimists feared. Newly released figures show that our merchandise trade surplus in 1989 fell by more than half to its lowest level in 10 years. And, ever since it peaked on Jan. 12, the dollars yo-yo motion has juddered erratically, signalling confusion to the money markets of the world where the mismanagement of a national economy is judged with a harsh and unforgiving coldness. The freshest banana peel under Mr. Wilson's foot is the report that inflation in January jumped from December's 5.1 per cent to 5.5 per cent -- right on the heels of Thursday's rise of more then half a percentage point in the Bank of Canada rate.