Re: [Gretl-devel] gretl bug: ordered probit model

On Mon, 9 Oct 2017, Artur T. wrote: >> However, I was thinking: can lagging the constant ever make sense, >> in any situation? Shouldn't const(-1) be a no-op? > I cannot think of any situation where const(-1) does make sense at > all. It was just by coincidence included in a list of regressors I > worked with. Nevertheless, I guess it would be good if gretl would > return an error in this case. Wouldn't it make sense to pre-check > whether there is any series (apart from the intercept) with variance=0? The problem is not as simple, as we need to guard against "constants in disguise", as for example exhaustive sets of dummies. The more I think about this, the more I'm convinced we should throw an error at any attempt to create lags of "const".