# What is the point in regression through the origin? [duplicate]

I am doing the Coursera Statistics Inference course and one of the questions is to find the regression through the origin, when the regression line has an intercept. Can you please explain what the point of this is? Why would you want to find the regression line through the origin when there is an intercept?

• The Coursera question can't be right. You can force the regression line to go through the origin, or you can allow the intercept to be what it wants to be. But you can't include an intercept term in the model and then have a zero intercept as well – Placidia Jan 11 '15 at 19:19
• @Placidia, I suspect the DGP / unbiased reg line has an intercept & the assignment is to fit a model w/o one. I suspect this is an exercise intended to illustrate the problems w/ suppressing the intercept. – gung - Reinstate Monica Jan 11 '15 at 19:30
• @Xi'an, this may not be a duplicate. That Q asks for the formula, whereas this Q asks for the reason behind this exercise. – gung - Reinstate Monica Jan 11 '15 at 19:41
• Perhaps that wasn't a close duplicate, but what about the questions here here, here, here, here, & here? – Scortchi - Reinstate Monica Jan 11 '15 at 20:17