Isovalue lines
In microeconomics, in a standard trade model with two products, an isovalue line is the vector of combinations for which the market value of total production is constant.{{Cite web |last=Fernández |first=Èric Roca |date=2019-07-11 |title=The Standard Trade Model |url=https://eric-roca.github.io/courses/international_trade/standard_trade_model/ |access-date=2024-11-27 |website=Èric Roca Fernández |language=en-us}}{{Cite web |title=Econ 325 - The Standard Trade Model |url=http://qed.econ.queensu.ca/pub/faculty/lewb/325_LecStandard.html |access-date=2024-11-27 |website=qed.econ.queensu.ca}} The formula for isovalue line V is:
in which:
Q is quantity
P is price
x and y are products.
For example: Assume an economy that only produces bread and wine and in which relative prices are fixed, say one bottle of wine equals the price of three breads. The isovalue line V (in a graph with bread as x and wine as y) slopes less than 45° downward. The exact slope is derived from the wine/bread price relation, in this case -1/3.