IG Economics 2.2 - How markets workmarket demandtotal effective demand of all consumerseffective demanddemand + ability to paydisposable incomeincome left to spend after taxmarket demand curvecurve that shows the total quantity demanded at any given pricecomplementary goodsgoods that are consumed together e.g: cars and petrolsubstitutesgoods that are similar and compete to satisfy the same consumer demandnormal goodsdemand for these rises as income risesinferior goodsdemand for these falls as income risesequilibriumwhen demand = supply, stableexcess supplyquantity supplied > quantity demandedexcess demandquantity demanded > quantity suppliedindirect taxa government can give this to increase price of a product, reducing its market supplysubsidypayment to producers from government to reduce costs of production