number of instruments greater than number of observations

[dddmb33]

hello
how can i fix the problem of receiving the message "number of instruments greater than number of observations"
thanks

[startz]

Without meaning to sound frivolous, get more observations or use fewer instruments.

[dddmb33]

but how can i choose the correct number of instruments

[startz]

You need as many, or more, instruments as you have right hand side variables. Past that, you'll have to explain what you're doing and see if someone has more specific advice.