T- technology can increase or decrease the production costs for a producer. R-related prices the change in resources from producing one good to another good. I- input prices if the price of inputs goes up, supply will decrease (shift left) if the price of inputs goes down supply will increase shift right. C- competition how many firms are competing. An increase in number of firms competing gives us an increase in supply, while a decrease gives us a decrease in supply. E- expectations this has to deal with hoarding behavior. If everyone expects the price of gold to be higher in the future, they will sell less of it now to take advantage of higher future prices. This causes a decrease in supply. However, if people expect the price of houses to drop in the future, then everyone will want to sell today, which will result in an increase in supply.