Suppose that a combination of public health warnings, school programs, a ban on advertising, and warnings on package labelling cut the demand for cigarettes in half (that is, the demand curve shifted left for cigarettes at any price by \(50 \%\) ). Using a supply-and-demand diagram of a competitive market, show the likely effect on equilibrium price and equilibrium quantity. Would you expect equilibrium quantity to change by \(50 \%\) ? Show how the answer depends on the slope of the supply curve.