Production and costs Flashcards
Production function
Q = f(K, L)
Q : output
K : capital input (building, machinery)
L : Labour input (employee)
short run : production function
K is fixed
L is flexible
long run: production function
(K, L) are flexible
Marginal product of labor and capital
∂Q(K, L) / ∂L = MPL
∂Q(K, L) / ∂K = MPK
isoquant
curve represents all combinations of inputs that allow a firm to produce a particular quantity of output.
marginal rate of technical substitution (MRTS)
is the negative value of the slope of the isoquant at a particular point
An isocost line
shows all of the input combinations that yield the same cost.
For a particular total cost level of C, the isocost line is:
C = RK + WL
R: the price per unit of capital (depreciation and interest rate)
W: the price per unit of labor (opportunity costs)
Solving for K (on the vertical axis) yields the downward-sloping straight line
K = R /C − WR / L
The cost-minimizing input combination satisfies two requirements:
– It lies on a given isoquant
– It lies on the lowest possible isocost line
At the optimal input combination, the isocost line is..
tangent to the isoquant (“tangency condition”), i.e. the slopes are equal
cost function
shows the minimum production cost for the output at the given input prices.
The cost function is therefore the sum of the conditional demands for the inputs weighted by the input prices.
The cost function is given by
C(W, R, Q) = WL(W, R, Q) + RK(W, R, Q)
How does output change if all inputs are increased? (Returns to scale)
Constant returns to scale –> Output rises proportionately
Increasing returns to scale –> Output rises more than proportionately
Decreasing returns to scale –> Output rises less than proportionately
How does cost change if output is increased?
Constant economies of scale –> Cost rises proportionately
Economies of scale –> Cost rises less than proportionately
Diseconomies of scale –> Cost rises more than proportionately