The poor availability of syntaxes of structural equation modeling

Abstract

The syntax or codes used to fit Structural Equation Models (SEMs) convey valuable information on model specifications and the manner in which SEMs are estimated. We requested SEM syntaxes from a random sample of 229 articles (published in 1998–2013) that ran SEMs using LISREL, AMOS, or Mplus. After exchanging over 500 emails, we ended up obtaining a meagre 57 syntaxes used in these articles (24.9% of syntaxes we requested). Results considering the 129 (corresponding) authors who replied to our request showed that the odds of the syntax being lost increased by 21% per year passed since publication of the article, while the odds of actually obtaining a syntax dropped by 13% per year. So SEM syntaxes that are crucial for reproducibility and for correcting errors in the running and reporting of SEMs are often unavailable and get lost rapidly. The preferred solution is mandatory sharing of SEM syntaxes alongside articles or in data repositories.