Which factor would most likely decrease consumer surplus?

An increase in taxes on goods and services would most likely decrease consumer surplus because it raises the effective price that consumers must pay for those goods and services. Consumer surplus is defined as the difference between what consumers are willing to pay for a product and what they actually pay. When taxes increase, the price consumers pay goes up, which narrows the gap between their willingness to pay and the actual price they pay. As a result, many consumers may find that they are paying a price closer to their maximum willingness, thereby reducing their overall surplus.

In the case of an increase in consumer income or a decrease in market prices, these factors would generally lead to an increase in consumer surplus. Similarly, an increase in the number of available substitutes would typically enhance consumer choice and lead to more competitive pricing, which can also increase consumer surplus. In contrast, increased taxes directly diminish the benefits consumers receive from their transactions, thereby reducing consumer surplus.