Microeconomics: Marginal Utility and Market Elasticity
Law of Diminishing Marginal Utility
As the consumption of a specific good increases, total utility increases, but at a decreasing rate. This occurs because marginal utility decreases (the level of satisfaction gained from each additional unit drops). People experience decreased utility when purchasing more of a certain good because they become increasingly satisfied, causing their incremental satisfaction level to fall.
This law is closely related to the law of diminishing returns.
Example: When we buy a Costanuss chocolate, our initial satisfaction level is high. However, as we continue to eat, our satisfaction increases less and less until the chocolate becomes unappealing. At that point, we can no longer eat more, and our satisfaction level begins to decrease.
Key Notes:
- As a product is consumed more, its marginal utility decreases.
- When a product is consumed less, its marginal utility or perceived value increases.
The Budget Line and Consumer Balance
The Budget Line (or Budget Balance) indicates the level of satisfaction based on an individual's income at different points. These points represent the maximum amount of goods people can purchase based on their income. If income is higher, the curve shifts upward compared to those with lower income levels.
Conditions for Consumer Equilibrium
- To achieve accuracy, the consumer is required to spend all income reflected in the budget line.
- The Marginal Utility and the ratio between goods should be equal. This state represents a point of balance.
Understanding Market Elasticity
Elastic Goods
A good is elastic when the quantity consumed varies significantly as a result of price changes. These products typically have substitutes and are versatile (having multiple uses).
Inelastic Goods
A good is inelastic when it has few substitutes and is less versatile. Examples include salt and insulin; whether the price is high or low, consumption will not change significantly.
Types of Elasticity
- Price Elasticity: The percentage variation in the quantity consumed of a product compared to the percentage change in its price.
- Income Elasticity: This shows how the quantity consumed of a product varies according to changes in the population's income level.
- Cross Elasticity: The percentage variation in the quantity consumed of "Good Y" compared to the percentage change in the price of "Good X."
Theory of the Firm
- Industry: The sum of all firms engaged in the same economic area.
- Long-term: A period long enough to produce changes in production levels by altering the size of the industry (e.g., more companies joining). Period: 5 to 10 years.
- Short-term: A period long enough to change production without changing the company's structure (e.g., optimizing efficiency). Period: 1 year.
- Medium-term: A period where more firms can enter or resource efficiency can be improved. Period: 1 to 5 years.
- Utility (Profit): Total revenue minus total costs.
- Total Income: Price multiplied by quantity.
- Total Cost: Fixed costs plus variable costs.