ESPA4221-4321 PENGANTAR EKONOMI MIKRO - Produksi dan Biaya Jangka Pendek

Production and Short-Run Costs

The lecture explains how firms make production decisions over different time horizons, how output responds to changes in inputs, and how production costs behave in the short run.

1. Time Horizons for Production Decisions

• Short run: At least one input is fixed, while other inputs can vary. The short run is defined by which inputs can be changed—not by a specific number of months or years. Firms make the best use of their existing facilities and equipment.
• Long run: All inputs can be changed, but the underlying production technology is assumed to remain unchanged. Firms may alter their scale, enter or expand a business, develop products, or reorganize production.
• Very long run: Technological change is possible. New technology may create new products or more efficient production methods.

2. The Production Function and Measures of Output

A production function describes the relationship between the inputs used in production and the output produced. The lecture focuses on capital as a fixed input and labor as a variable input.

• Total product (TP): The total amount of output produced in a given period.
• Average product (AP): Output per unit of a variable input. For labor (L):
  • AP = TP ÷ L
• Marginal product (MP): The change in total output resulting from using one additional unit of a variable input:
  • MP = change in TP ÷ change in labor

The lecture uses a table and graphs to illustrate how TP, AP, and MP change as labor increases while capital is held fixed.

3. Diminishing Returns

The law of diminishing returns states that when more units of a variable input are added to fixed inputs, the additional output eventually becomes smaller.

• Initially, adding workers may cause total output to rise quickly.
• As diminishing returns set in, each additional worker adds less output than the previous one.
• When TP reaches its maximum, MP is zero. Beyond that point, an additional worker would reduce total output.
• MP’s position relative to AP indicates whether AP is rising or falling. AP reaches its maximum where MP crosses it.

4. Short-Run Costs

Total cost consists of fixed and variable costs:

• Total fixed cost (TFC): Does not change with output in the short run, such as costs associated with fixed inputs. These are also called overhead or unavoidable costs.
• Total variable cost (TVC): Changes with the level of production, rising as output increases and falling as output decreases. These are also called direct or avoidable costs.
• Total cost (TC):
  • TC = TFC + TVC

The lecture also defines costs per unit:

• Average fixed cost (AFC): TFC divided by output.
• Average variable cost (AVC): TVC divided by output.
• Average total cost (ATC or AC): TC divided by output.
  • ATC = AFC + AVC
• Marginal cost (MC): The increase in total cost from producing one additional unit:
  • MC = change in TC ÷ change in output

5. How Production and Cost Curves Relate

• With fixed input prices, higher output per worker tends to lower AVC because each worker’s cost is spread over more output.
• AVC and ATC are generally U-shaped: costs per unit may fall at first, then rise as diminishing returns make additional output more costly.
• MC tends to fall while MP is rising and to rise as MP falls. The lecture describes MC as the cost-side counterpart of the MP relationship.
• AFC declines as output increases because a fixed cost is spread across more units.

6. Capacity

The lecture defines a firm’s capacity in terms of the output it can produce at minimum ATC—not the absolute maximum amount it could physically produce.

• Producing beyond this level tends to increase average total cost.
• Producing below it means the firm is operating below capacity; average cost may be higher than at the minimum-ATC output.

Overall, the lecture emphasizes that production and cost decisions are linked. How effectively variable inputs add output affects marginal and average costs, while fixed costs and the firm’s scale also shape its cost curves and capacity.

Speakers and Sources Featured

• An unnamed lecturer or narrator presenting an Open University introductory microeconomics lesson.
• Tables and graphs referred to in the lecture to illustrate production and cost relationships.
• No other named speakers or external sources are identified in the subtitles.