What Are the Cross Elasticities of Demand and Supply?

Economists have second and third homes paid for by the of the anti trust consulting business. They are very careful about trying to sort of be above the fray and say the truth, but actually not say anything anywhar. It often is portrayedtono, you've hit them, imean. What you need to know is the cross elasticities of demand and supply. Given that, so if the price of an iphone changes and an upwards action, what happens to the prices of? Then we don't know what to do.