Law of demand and supply is one of the most basic principles in economics. An ideal state of market equilibrium is reached when the supply in the market exactly matches the demand of the market. However, this equilibrium in market is difficult to achieve and sustain due to a lot of related elements that govern demands and supplies. In fact, it is strongly suggested that for an economy to grow, it is important that demand is always slightly higher than the supply. Interestingly, this theory of economics is also applicable to parenting.