The heart of the book is an essay, 'Deep structure and typology'. It treats the role of deep structure in transformational grammar in accounting for cross-linguistic generalizations. Birnbaum's approach is to postulate a model of grammar containing levels of representation called 'typological deep structures' corresponding to typological similarities among languages. The hierarchical, abstract, and autonomous nature of these structures weaken the ability of the model to explain 'why [some] language structures are possible and not others.' [to appear in General Linguistics]
"Problems of Typological and Genetic Linguistics Viewed in a Generative Framework,"
Colorado Research in Linguistics: Vol. 3.
Available at: https://scholar.colorado.edu/cril/vol3/iss1/1