someone help me with sign restrictions.

[karl5914]

I just want to restrict my parameters smaller than 0 as a test whether the parameter is smaller than 0, I am just wondering if some one can help me with this. Thanks

[TomDoan]

In what situation? Linear model? Non-linear? If you're just interested in testing, the usual way to handle that is to estimate unrestricted, then restrict the parameters of interest to zero as a Wald test or LR test.