Technical efficiency-When firms combine inputs to produce a given output as inexpensively as possible. Production contract curve-Curve show all technically efficient combinations of inputs. Production possibilities frontier-Curve showing the combinations of two goods that can be produced with fixed quantities of inputs.  Technical efficiency - When firms combine inputs to produce a given output as inexpensively as possible.  Production contract curve - Curve show all technically efficient combinations of inputs.  Production possibilities frontier - Curve showing the combinations of two goods that can be produced with fixed quantities of inputs