Hello, In the process of running rare event logits, I am having trouble specifying the "order.by" parameter for the computation of robust standard errors. When running the command: /zelig(event ~ variablea + variableb + variablec, model="relogit", data=sample, tau = 0.0009271, case.control = "weighting", //robust = list(method = "vcovHAC", order.by = ~companyid)//)/ I receive the following error: /Error in zelig3relogit(res = list(coefficients = c(3.98562294911716, 0.131560761736764, : Object "rob" not found / However, when running the above command with "robust = TRUE", I receive the results as expected. Has anyone encountered a similar issue? Am I using the wrong syntax for the robust parameter and order.by? Thank you in advance for any assistance, Ben -- Benjamin L. Hallen Doctoral Candidate Stanford Technology Ventures Program (http://stvp.stanford.edu) Email: hallen(a)stanford.edu Office: 650-725-1631 Cell: 434-825-4978