Understanding macro syntax

[Jeremy Wells]

I use a macro to define the URL for a dataset downloaded from Harvard Dataverse using copy:

local unvotingdata "https://dataverse.harvard.edu/api/access/datafile/2839238?format=original"
copy `unvotingdata' "RawVotingdata.dta", replace

This returns a "varlist not allowed" error, but if I enclose the call to the macro in double quotation marks, it works fine:

local unvotingdata "https://dataverse.harvard.edu/api/access/datafile/2839238?format=original"
copy "`unvotingdata'" "RawVotingdata.dta", replace

I copy other datasets from URLs input as macros without double quotation marks, so I'd appreciate an explanation for why Stata needs them here.

[Clyde Schechter]

I believe it is the = character in the URL that causes this problem.