<p>ARCH was made synonym of GARCH by voting on the synonym proposal.<br>
(This way was preferred over mapping both to <code>arch-garch</code> as nobody was able to vote for or even suggest the latter synonyms because nobody has the necessary >=5 rep points in the non-existing <code>arch-garch</code> tag. - thanks to @amoeba for the note)<br>
The change took place on January 24, 2017.<br>
The case is closed.</p>
