To begin with, it may be useful to make clear which elements in the economic system we usually take as given, which are the independent variables of our system and which are the dependent variables.
In other words, property rights appear to be a dependent variable, whereas subjective value, utility, au filimenti, and market prices are portrayed as independent ones.
In regression, y is the variable we want to predict (the dependent variable). In this example, y is the shear strength. x is the independent variable — in this case, the age of the propellant.
So we have one independent variable – receiving the voucher or not – and a bunch of possible dependent variables, like earnings, education, and health outcomes.