In a market at equilibrium, how does the analysis of marginal costs and benefits influence consumer surplus when a new tax is introduced?

In a market at equilibrium, the price of goods is set where the quantity demanded by consumers equals the quantity supplied by producers. When a new tax is introduced, it raises the price consumers have to pay, which can change their purchasing decisions. This means that the marginal benefit, or the satisfaction gained from consuming one more unit, may no longer equal the marginal cost, or the price they must pay after the tax. As a result, consumer surplus, which is the difference between what consumers are willing to pay and what they actually pay, decreases because consumers either buy less or stop buying altogether. For example, if a tax increases the price of a popular snack from $2 to $2.