1. An Introduction to Supply
Supply is the amount of a product offered for sale at all possible prices in a market.
The Law of Supply states that more product will be offered for sale at higher prices than at lower prices.
Normal individual supply curves have a positive slope that goes up from left to right; if price goes up, quantity supplied goes up as well.
The market supply curve is similar to the individual supply curve, except that it shows the quantities offered by all producers in a given market.
Change in quantity supplied refers to a change in the quantity of a product offered for sale in direct response to a change in price.

2. Change in Supply
Whereas a change in quantity supplied occurs only when prices change, a change in supply occurs when quantities change even though price remains constant.
Factors that can cause a change in supply include cost of resources, productivity, technology, taxes, subsidies, government regulations, number of sellers, and expectations.

3. Elasticity of Supply
Supply elasticity is a measure of the degree to which the quantity supplied responds to a change in price.
Like demand, supply can be elastic, inelastic, or unit elastic.
Production considerations alone determine supply elasticity. If a firm can adjust to new prices quickly, then supply is likely to be elastic. If adjustments take much longer, then supply is likely to be inelastic.

4. The Production Function
The production function is a graph or figure that shows how a change in one production variable affects total output.
Production can be analyzed in terms of short- run or long-run relationships between inputs and outputs.
Marginal product is the extra output or change in total product caused by adding one more unit of input.

5. Stages of Production
Marginal product changes as more workers are added.
In Stage I of the production function, the marginal product increases with each additional worker.
Stage II of the production function operates on the principle of diminishing returns; marginal products are still positive, but decrease steadily.
In Stage III of the production function, the company has hired too many workers, and they interfere with one another and with production, causing marginal product to become negative.

6. Finding Marginal Cost
The costs that an organization incurs even when there is little or no activity are fixed costs, or overhead.
Variable costs are usually associated with labor and raw materials and change with the business’s rate of operation or output.
Total cost is the sum of fixed and variable costs.
Marginal cost is the extra cost incurred to produce one more unit of output.

7. Finding Marginal Revenue
Average revenue is the average price of every unit of output.
Total revenue is all of the revenue a business receives.
Marginal revenue is the extra revenue a business receives from the production and sale of one additional unit of output.
Marginal revenue is the most important measure of revenue.

8. Profit Maximization and Break-Even
Profitability is affected by both costs and revenue.
The profit-maximizing quantity of output is the volume of production where marginal cost and marginal revenue are equal.
The break-even point is the level of production that generates just enough revenue to cover total operating costs.
The Internet is one of the fastest-growing areas of business today.
E-commerce has much lower overhead and does not require as much inventory as traditional retail stores, so the break-even point of sales is much lower.