why would zero productivity cause bias when a variable is zero, the result will be a bias in a survey of employees? why would a variable be zero if productivity is zero what would it be if the number of people in a variable is zero? why do we want to leave output at zero how does zero productivity affect the explanatory variable why is it important to leave the variable zero when there is zero workers which variable would create bias when a variable has zero employees, it would be equal to zero? why would it be a bias to let productivity be zero why is it necessary to have a variable zero and have a discontinuity? which variable has zero workers how do you find the zero of a variable? what is the difference in a zero and zero employee when the number of workers is zero, the output variable how to calculate probability of zero in dummy variable why does zero mean zero what is the bias for the variable productivity why if the number of workers is zero would it bias