In a number of statistical packages including SAS, SPSS and maybe more, there is an option to “suppress the intercept”. Why would you want to do that?

**Answer**

If for some reason you *know* the intercept (particularly if it is zero), you can avoid wasting the variance in your data for estimating something you already know, and have more confidence in the values you *do* have to estimate.

A somewhat oversimplified example is if you already know (from domain knowledge) that one variable is (on average) a multiple of another, and you are trying to find that multiple.

**Attribution***Source : Link , Question Author : user333 , Answer Author : Nick Sabbe*