I am trying to understand the colinearity assumption for linear regression. I have produced this counter example which I can't explain:
Suppose we are modelling the sales of a shop by the sea and on any given day the shop sells two items, buckets and spades. Buckets cost £2 and spades cost £1. The relationship should be:
Y = 2B + S
There is clearly colinearity going on between the variables buckets and spades as they are generally bought together.
Any help?