# the relationship between Returns to Scale and shape of Production Possibility Frontier (PPF)?

Guys any material that discusses the above in detail for a two commodity case?

• PPF is for Production Possibility Frontier (for all non english economists) Commented Oct 19, 2023 at 19:54
• In what context are you interested in it? You mean in the sense of: „if I consume more of A, A will become cheaper“? Commented Oct 19, 2023 at 19:55
• This might help: qr.ae/pGLAbN
– Amit
Commented Oct 20, 2023 at 2:51
• @vanya I wanted to understand the geometry of the PPF for a two commodity case like conditions for it to be concave/convex/linear depending on the returns to scale each commodity exhibits. Commented Oct 20, 2023 at 4:55

There is an indirect relationship. PPF size and shape is determined by production functions. Set of production functions $$F_i= AK{^0.5}L^{0.5}$$ will produce different PPF then set of production functions $$F_i= A(K+L)^{0.5}$$.
• @Giskard yes production functions do produce PPF. PPF is derived from production functions for goods. If good A has production function $A=10L$ and good B production function $B=L$ then PPF for A and B if country has L=100 is $100 = A/10 + B$. If you change production function for B to $B=10L$ you get new PPF $100=A/10 + B/10$. How else can you get PPF if not by using production functions for goods? Commented Oct 30, 2023 at 14:41