McGrath asks "Were there Child equivalents in other countries":
For Germany it is the famous Erk/Böhme.
Erk, Ludwig: Deutscher Liederhort : Auswahl der vorzüglicheren deutschen Volkslieder ; nach Wort und Weise aus der Vorzeit und Gegenwart / ges. und erl. von Ludwig Erk. Nach Erk's hs. Nachlasse und auf Grund eigener Sammlung neubearb. und fortges. von Franz M. Böhme. - Leipzig 1893-94
(Treasure of German songs : Selection of the more excellent German folk songs ; with words and tunes from past and present / collected and commented by Ludwig Erk. From his unpublished manuscripts and with own collections newly edited and continued by Franz M[agnus] Böhme. - Leipsic 1893-1894
Note that he didn't only collect ballads, but all kinds of folk songs, neatly categorized, and with a rather vast bibliography of the sources he drew from. Here I found a lot more songs which I choose for my own singing.
The 2 vols. with 1060 entries were reprinted in 1963, and without this outstanding work a lot of folk songs would have been forgotten, because they were sung less and less in his time.
Maybe it may serve as an argument against Ian in his role as advocatus diaboli; I'm sure the same can be said about Child's work.
Important in both scholars' works is the vastness of their collections, bringing together a corpus drawn from other collections known less, and giving a fine starting point for further researches.

Wilfried