EC201 Micro Flashcards
SR v LR distinction
SR: period of time where one or more of a firm’s inputs cannot be changed
No opp.cost in SR -> one price for everything
LR: period of time in which all inputs can be changed
All opp.cost -> multiple prices
Profit Maximisation: Standard Assumption
- Profits = revenue - opportunity cost
- Objective of shareholders who control the firm and do not work for the firm
- Simple model starts with a production function or cost function
- Ignores the fact that the firm is an organisation run by people who have individual objectives and agendas
- Ignores conflicts of interest between investors and senior managers
- Competition: if a firm can at best make zero profit, it has to maximise profits to stay in business
- Incentives generated by the financial sector and the market for managers (reputation, reward packages, takeover threat)
Risk Taking
- Risk management is necessary
- Managing the risks of long term decisions is difficult
- Some incentive schemes, e.g. bonuses and stock options may encourage risk taking
- The situation is complicated by asymmetric information and incomplete contracts
- Carney: “Compensation schemes overvalued the present and heavily discounted the future, encouraging imprudent risk taking and short-termism”
PDV of Profits
- Standard assumption that firms maximise the present discounted value V of profits,
- Measuring revenue can be problematic “principally due to the accelerated recognition of commercial income and delayed accrual of costs”
- Costs are complicated if the firm has durable equipment, intellectual property or long run contracts
- Economic cost (opportunity cost) can be different from cash flows to providers of inputs and from accounting costs
Opportunity Cost (Economic Cost)
- Defined as the value of an input in its best alternative use
- For something a person or firm is buying now, the opportunity cost is the current price
- Can be impossible to measure accurately but useful to think about when making decisions
The Cost of Capital
- If you save p at interest rate r for 1 year you have cash (1+r)p next year
- If you buy the capital good, used it and sold it, you would have cash p next year
- The difference in the amount of cash is the opportunity cost of capital rp
- If p = 1 the cost of capital is r
- The cost of capital depends on: rate of physical or technical deterioration, continuation or not of technical support, technical obsolescence, changes in the price of the capital good, installation and transaction costs
- Taxes
Why do management practices differ across firms and countries?
- Good management makes a big difference to profits and other measures
- Huge variation across and within countries and industries
- Competition is associated with good management
- Monitoring, targets and incentives
Low cost of capital firms: badly managed firms?
- If capital is obsolete (ood) it may have zero or even negative opportunity cost (pay to scrap it)
- Land may have opportunity cost but that is ignored because there is no associated cash flow -> land is a fixed factor of production
- Firm may continue even though it’s making an economic loss. Low debt avoids cash flow problems
- Appointing eldest son as CEO is associated with bad management
Law of Diminishing Marginal Returns
• If one input increases while the others are held constant, the marginal product of that input falls as output expands
• Example: labour in agriculture
With a fixed amount of land, seed, machinery etc. beyond a certain point the extra output from increasing labour starts falling
Cost Functions
• The cost function c(v,w,q) is the minimum cost of producing output q using capital K and labour L with prices v and w
• This definition assumes all inputs can be varied (LR cost function)
• You find the cost function by:
Finding the levels of K and L that minimise vK + wL subject to the constraint f(K,L) > q and non negativity constraints K > 0, L > 0
• K(v,w,q) and L(v,w,q) -> sometimes called conditional fact demand as they depend on (v,w,q)
• The cost function is:
C(v,w,q) = vK(v,w,q) + wL(v,w,q)
• Check for: increasing inputs increases outputs, convexity
Properties of the Cost Function I (facts)
1) Increasing in output q
2) Homogeneous of degree 1 in input prices v,w (double price = double C(v,w,q))
3) Non-decreasing in input prices
4) Concave in input prices
5) Shephard’s lemma for cost functions
Properties of the Cost Function II
- Cost minimisation at a tangency
- If q2 > q1, producing q2 costs more than producing q1 so the cost function c(v,w,q2) > c(v,w,q1) the cost function is increasing in output
- Conditional factor demand K(v,w,q) & L(v,w,q) are homogeneous of degree 0 in input prices
- The input combination that minimises the cost of producing q does not change, but the cost of the inputs is multiplied by k
- If all input prices are multiplied by k > 0 the isocost line doesn’t change (homogeneous of degree 0)
- The cost function is homogenous of degree 1 in input prices
- If the price of K rises from vA to vB, the gradient of the isocost line changes, the cost of producing q1 increases
Thingies and Homogeneity
Thingy Homo
Isocost 0
Cost Function 1
CFD 0
Only the cost function is homosexual.
Low Wages and Labour Productivity
• Which way does causation go?
• Low production thus low wages
Or
• Low wages thus low production
• If wages are low then firms substitute labour for capital. The Marginal product of labour is then lower?
• Low productivity may be a consequence of low wages & high cost of capital
• Post financial crisis, harder & more expensive for firms to borrow. Low investment
Returns to Scale (check)
- A property of the production function
- With constant returns to scale, multiplying inputs by any m > 0 multiplies output by m so f(mK,mL) = mf(K,L)
- If f(mK,mL) > mf(K,L) there are increasing returns to scale
- If f(mK,mL) < mf(K,L) there are decreasing returns to scale
Economies of Scale
- A feature of a cost function
- Average cost AC = total cost/output
- There are economies of scale if AC decreases with output
- There are diseconomies of scale if AC increases with output
- Increasing returns to scale in the production function implies economies of scale
Volume Effects
- Capacity depends on volume
- Cost depends on surface area
- Increasing size reduces cost per unit of output
There can’t be decreasing returns to scale?
- There might be some fixed input that cannot be doubled
- There may be managerial diseconomies of scale -> management difficulties grow faster than the number of people
- The transition from a small to a large organisation can be difficult
Other influences on costs
- The production function assumes a single unchanging product and that the output from a given output is fixed by technology
- This may not be so owing to economies of scope/learning by doing
- Costs before production starts e.g. R&D, websites etc
Economies of scope
- One firm producing a range of related products has cost advantages over firms producing single products
- When a firm gains efficiencies from selling a wider range of products
- E.g. selling petrol and groceries at a petrol station (same input (labour and capital), can sell both types of goods for same pay)
Learning by Doing
• As firms build experience in producing a product the average cost of producing the product falls
Economic Loss
Economic loss is a term of art which refers to financial loss and damage suffered by a person such as can be seen only on a balance sheet rather than as physical injury to the person or destruction of property.
Isoquant
• Isoquants show the combinations of inputs that can produce a given quantity of output = indifference curves in consumer theory
The isoquant curve is a graph, used in the study ofmicroeconomics, that charts all inputs that produce a specified level of output. This graph is used as a metric for the influence that the inputs have on the level of output or production that can be obtained. The isoquant curve assists firms in making adjustments to inputs to maximize outputs, and thus profits. The curve represents a consistent level of output
Isocost
• Isocost lines show the combinations of inputs that cost the same = constant expenditure lines
In economics an isocost line shows all combinations of inputs which cost the same total amount. Although similar to the budget constraint in consumer theory, the use of the isocost line pertains to cost-minimization in production, as opposed to utility-maximization.