Approval and publication process information
When in doubt, always cite the date of print, rather than online, publication. Journals often provide the date of print publication in either the header or footer.
Online-only journals represent an important exception to this rule.
A brief aside on scholarly publication: According to this information, Castiglione and Infante submitted this article, on which they likely had been working for at least a year, to the Journal of Cultural Economics for review on March 28, 2013. The journal accepted it for publication over two years later. Another year passed before the journal published their work in print.
In other words, four or five years elapsed between the genesis of their project and its successful publication. This demonstrates why scholarly literature can be a poor resource for timely analysis of current events.