Do 2DES and 3DES2 have the same effective key length?
Definitely a mistake. The text clearly contradicts itself.


  ... 2DES has an effective key length of 57.


And later...


  There does not
  appear to be a meet-in-the-middle attack on 3DES2 however, so that its key length of 112 is also
  its effective key length.


which clearly contradicts


  2DES, although having the same effective key length as 3DES2 and offering what appears
  to be the same or at least adequate security, is not popular in practice.


As a bit of an aside, 3DES2 is considered by NIST to have an effective key length of at least 80 bits, but definitely not the full 112 bits, due to its vulnerability to known-plaintext attacks with $2^{40}$ blocks.