Fixed a bug in psid_read() where including 1968 variables caused a join failure because ER30001 was dropped before being used as a join key for the 1968 family file merge.
Fixed a bug in psid_reshape() where the rename step crashed when ER30001 was absent from the data frame after psid_read() processing.
psid_str() for variables names in earlier waves. Thanks Jiao G. for pointing this out!