Serbo-Croatian is developing stem-based prosody. Why so?

Evidence is presented that Serbo-Croatian, in contrast to other Slavic languages
with lexical prosody, is developing a prosodic system in which stressed non-stem
material is avoided and surface stress is becoming a property of the word stem. Five
case studies are shown in which stress is moving from non-stem material to stems.
We analyse the general move towards stem-stressed prosody as the final step in a
chain of language changes initiated by the Neo-Štokavian retractions, which were
automatic and contrast-preserving, but led to a massive removal of stress from
inflectional endings. We discuss the general reasons behind this language change
in terms of markedness and, more specifically, the constraints proposed within
Optimality Theory. We propose an analysis of the change under consideration in
terms of a promotion of the markedness constraint STEMSTRESS, which requires
stems to be stressed independently of lexical prominence.