PIE as a pidgin?

Hello, all:

I was reading _Historical Linguistics_ by Winifred P. Lehman (3rd Ed., Routledge, 1992), and I came upon what I thought was an interesting statement on pp. 136-137: "The most widely discussed suggestion of a pidgin-like origin for a proto-language is that of Trubetzkoy (1939). Observing that Proto-Indo-European included characteristics that were found in neighboring languages, he suggested that instead of ascribing these to one language in the course of its development, they indicated a pidgin origin for Proto-Indo-European. In view of Trubetzkoy's prestige, the suggestion continues to be cited, even though there is even less evidence for it than for the suggestion of Celtic influence on French and English."

To what characteristics and from which languages would Trubetzkoy have been referring? How valid is this suggestion? Was this an attempt at a counter-argument against including PIE in a macro-family such as Nostratic. According to Encyclopædia Britannica, Holgar Pedersen had come up with the concept of Nostratic in 1903 (( http://www.britannica.com/eb/article?eu=233&tocid=0&query=nostratic&ct=eb )). Lehman does refer to Nostratic, but not in the context of Trubetzkoy (( _Historical Linguistics_ by Winifred P. Lehman (3rd Ed., Routledge, 1992), pp. 89-90 )).

Thanks a lot and Happy Holidays to all:

Andy Howey