Guitar makers use a special kind of wood to build their instruments. But the trees that produce that kind of wood are running out. Over time, what will probably happen to the overall supply of new guitars?
The supply will probably go up. The supply will probably go down.
Overall supply is the total amount of a good or service that producers make and sell. There are several things that can make overall supply go up or down. The table below shows how changes to these things might affect overall supply.
 | Resources | Number of producers or suppliers | Expected change in demand
Supply goes up | when resources cost less or are easier to get | when there are more producers or suppliers | when demand is expected to go up
Supply goes down | when resources cost more or are harder to get | when there are fewer producers or suppliers | when demand is expected to go down
Producers are people or companies that make goods or provide services. Suppliers are people or companies that sell goods or services. New inventions or technologies can also help workers produce goods and services more quickly. As a result of these changes, the supply of a good or service will often go up.
Wood is a resource that is used to make guitars. The trees that produce wood for guitars are running out, so this kind of wood will be harder to get. Since this kind of wood is becoming harder to get, it will be harder to make new guitars. So, over time, the supply of new guitars will probably go down.