ECON20002 Lecture Notes - Lecture 14: Marginal Cost, Marginal Product, Production Function
Document Summary
If k is fixed and l is variable then: fc = rk and vc(q) = wl*(q) Firms can vary both labour and capital to minimise costs. Can be fixed costs won"t be due to fixed factors of production. To minimise costs of producing q1 the firm must find the lowest isocost line that is tangent to the isoquant q1. Since the slope of the isocost is -w/r, hence at the optimum point the following relationship holds: Optimal point slope of isoquant = slope of isocost. Lhs is additional output from spending more on labour. Rhs is additional output from spending more on capital. Deriving the cost-minimising input choice to produce output involves using the following conditions: Optimal input choice must satisfy the tangency condition. Optimal input choice must be on the production function. Two equations yield the optimal input choices (l*, k*) as functions of w, r, and q0. Known as conditional input demands for the firm.