The poor availability of syntaxes of structural equation modeling.

Area of Science:

• Statistics
• Quantitative Psychology
• Econometrics

Background:

• Structural Equation Models (SEMs) rely on syntax for specification and estimation.
• Reproducibility in SEMs is challenged by the inaccessibility of estimation code.
• Software like LISREL, AMOS, and Mplus are commonly used for SEM analyses.

Purpose of the Study:

• To assess the availability and loss rate of SEM syntaxes.
• To investigate factors influencing syntax accessibility over time.
• To advocate for improved practices in sharing SEM code.

Main Methods:

• A random sample of 229 articles using SEMs (published 1998-2013) was selected.
• Requests for SEM syntaxes were sent to corresponding authors.
• Response rates and syntax retrieval success were documented.

Main Results:

• Only 24.9% of requested SEM syntaxes were obtained.
• The odds of syntax loss increased by 21% annually.
• The odds of obtaining a syntax decreased by 13% annually.

Conclusions:

• SEM syntaxes crucial for reproducibility are often unavailable and lost rapidly.
• The time elapsed since publication significantly impacts syntax availability.
• Mandatory sharing of SEM syntaxes with articles or in repositories is proposed.