Thanks as usual to Kit Baum a new module called

Type “ssc install dcreate” in Stata to install the command. After installation type “help dcreate” for instructions and examples.

I have been using earlier versions of

Arne

Carlsson F, Martinsson P. 2003. Design techniques for stated preference methods in health economics. Health Economics 12: 281-294.

Cook RD, Nachtsheim CJ. 1980. A comparison of algorithms for constructing exact D-optimal designs. Technometrics 22: 315-324.

Zwerina K, Huber J, Kuhfeld W. 1996. A general method for constructing efficient choice designs. Working Paper, Fuqua School of Business, Duke University.

**dcreate**is now available on SSC.**dcreate**creates efficient designs for discrete choice experiments using the modified Fedorov algorithm (Cook and Nachtsheim, 1980; Zwerina et al., 1996; Carlsson and Martinsson, 2003). The algorithm maximises the D-efficiency of the design based on the covariance matrix of the conditional logit model.Type “ssc install dcreate” in Stata to install the command. After installation type “help dcreate” for instructions and examples.

I have been using earlier versions of

**dcreate**on various projects over the past decade or so, but I haven’t until recently found a way to make it general enough to (hopefully) be useful to others. There are bound to be some teething problems, so please let me know about any issues you come across.Arne

**References**Carlsson F, Martinsson P. 2003. Design techniques for stated preference methods in health economics. Health Economics 12: 281-294.

Cook RD, Nachtsheim CJ. 1980. A comparison of algorithms for constructing exact D-optimal designs. Technometrics 22: 315-324.

Zwerina K, Huber J, Kuhfeld W. 1996. A general method for constructing efficient choice designs. Working Paper, Fuqua School of Business, Duke University.

## Comment