a. To find the initial market equilibrium quantity (Q∗) and price (P∗), we need to solve the supply and demand equations simultaneously.
Demand equation: P = 98 - 9Q
Supply equation: P = -2 + Q
Setting the two equations equal to each other:
98 - 9Q = -2 + Q
Combining like terms:
10Q = 100
Dividing both sides by 10:
Q = 10
Substituting the value of Q back into either equation (let's use the demand equation):
P = 98 - 9(10)
P = 98 - 90
P = 8
Therefore, the initial market equilibrium quantity (Q∗) is 10 billion packs per year, and the price (P∗) is $8 per pack.
b. After the per-unit tax of $t is imposed, the new equation of the market supply curve can be derived by adding the tax to the original supply equation:
New supply equation: P = -2 + Q + t
To find the new market equilibrium quantity (Q∗tax) and price (P∗tax), we need to solve the new supply equation and the demand equation simultaneously:
Demand equation: P = 98 - 9Q
New supply equation: P = -2 + Q + t
Setting the two equations equal to each other:
98 - 9Q = -2 + Q + t
Combining like terms:
10Q = 100 + t
Dividing both sides by 10:
Q = 10 + 0.1t
Substituting the value of Q back into either equation (let's use the demand equation):
P = 98 - 9(10 + 0.1t)
P = 98 - 90 - 0.9t
P = 8 - 0.9t
Therefore, the equations for the new market equilibrium quantity (Q∗tax) and price (P∗tax) as functions of the tax (t) are:
Q∗tax = 10 + 0.1t (market equilibrium quantity)
P∗tax = 8 - 0.9t (market equilibrium price)
c. The government's tax revenue from the cigarette tax is equal to tQ. Using the equation for Q∗tax from the previous part, we can write down an equation for the government's tax revenue as a function of the size of the tax:
Government's tax revenue = t * Q∗tax
Government's tax revenue = t * (10 + 0.1t)
Government's tax revenue = 10t + 0.1t^2
d. If the government sets the cigarette tax at t = $1 per pack, we can calculate the new market equilibrium quantity and price after the tax (Q∗tax and P∗tax):
Q∗tax = 10 + 0.1t
Q∗tax = 10 + 0.1(1)
Q∗tax = 10.1 billion packs per year
P∗tax = 8 - 0.9t
P∗tax = 8 - 0.9(1)
P∗tax = 7.1 dollars per pack
Therefore, after the tax of $1 per pack, the new market equilibrium quantity (Q∗tax) is 10.1 billion packs per year, and the price (P∗tax) is $7.1 per pack.
To calculate the percentage of the $1 tax passed on to buyers as a price increase, we can use the following formula:
Percentage passed on = (