Predict the effect on the price of at least one related product of each of the following events:
(a.) Winter snowfall is at a record high in the interior of British Columbia, but drought continues in Quebec ski areas.
(b.) A recession decreases employment in Oshawa automobile factories.
(c.) The French grape harvest is the smallest in 20 years.
(d.) The province of Ontario cancels permission for campers to cut firewood in provincial camp grounds.