International Journal of Population Studies (IJPS) is an open-access journal under AccScience Publishing. All articles published in IJPS can be freely accessed from the journal website. In order to ensure contents are freely available and maintain publishing quality, Article Process Charges (APC) are levied on all authors whose papers are accepted for publication after peer-review to cover the costs incurred in manuscript processing, such as copy-editing, typesetting, publishing, content depositing and archiving processes. Articles that do not require peer-review such as letters, editorials, corrigenda, and addenda will be published free of charge. For more details, please refer to AccScience Publishing Article Processing Charges.

In IJPS, withdrawal of a submission refers to the removal of a new submission, a paper currently under peer-review, an accepted paper, or an Article in Press from the online submission system. In the event that authors insist on withdrawing a submission on unethical and unreasonable grounds (Article Processing Charges mentioned *unethical and unreasonable reasons*), a submission withdrawal fee at 30% of the prevailing Article Processing Charge will be levied on the authors. Submission withdrawal is also possible for accepted papers that have not been formally published, including the newly accepted papers and Articles in Press. Authors should note that any amounts of paid Article Processing Charge will not be refunded if their accepted papers or Articles in Press are withdrawn on the grounds of academic misconduct and ethical violations in research and publication.