一、問答申論和計算題(共 15 分)
Consider a market where the demand function is \( Q_d = a - b \times P \) and the supply function is \( Q_s = k \times P \), with \( P \) representing the price, and \( Q_d \) and \( Q_s \) representing the quantity demanded and supplied, respectively. The parameters \( a \), \( b \), and \( k \) denote specific constants in the equations. If the government provides a subsidy of $1 per unit, calculate the deadweight loss. Is this loss greater, equal to, or less than the case if the government imposes an unit tax of $1 per unit? Why?