Foreign and UTF-8 on OS X

Jim,

    In particular, when I use the foreign package to export a  
dataframe to SPSS, the data file looks good, but the command file  
contains a mix of ASCII and UTF-8 quotation marks. For example,  
executing ...
[...]
Why am I getting a mix of UTF-8 and ASCII?

This is likely an issue with the `foreign' package. This is not Mac- 
specific, I have just checked and I get the same behavior on Linux  
(in UTF-8 locale, en_US.UTF-8 in my case).

Is it valid to mix UTF-8 and ASCII in the same file?

Technically, yes, the resulting file is a valid UTF-8 file. I don't  
know whether SPSS supports it, though (and I cannot check that).

Cheers,
Simon