command collapse（sum）imports is unrecognized

[Kendal zhang]

Nothing.

[Leonardo Guizzetti]

Two issues are that:

• your data example never satisfies the condition that importer==exporter
• the parentheses that you have pasted as your command are not the typical ASCII parentheses, probably copied from a PDF, so I would retype those characters

Simplifying the command by focusing on the unconditional sum of imports for the entire dataex presented and replacing those parentheses works. I cannot replicate your problem.

[Kendal zhang]

Two issues are that:

• your data example never satisfies the condition that importer==exporter
• the parentheses that you have pasted as your command are not the typical ASCII parentheses, probably copied from a PDF, so I would retype those characters

Simplifying the command by focusing on the unconditional sum of imports for the entire dataex presented and replacing those parentheses works. I cannot replicate your problem.

Thanks a lot.