EXHIBIT 24
POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints Frederick Bogdan, Robert Gutowski, Cecilia Aza, Kelly Diep and Vernon
Archibald, and each of them, his true and lawful attorney-in-fact to:

1.	prepare and execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of MSCI Inc. (the
"Company"), any and all Forms 3, 4 and 5 required to be filed by the undersigned
in accordance with Section 16 of the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), and the rules thereunder;

2.	prepare and execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of the Company, any Form
144 Notice under the Securities Act of 1933, as amended (the "Securities Act");

3.	do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4, 5 or
144 and timely file such form with the United States Securities and Exchange
Commission and any stock exchange or similar authority; and

4.	take any other action of any type whatsoever in connection with the foregoing
which, in the opinion of such attorney-in-fact, may be of benefit to, in the
best interest of, or legally required by, the undersigned, it being understood
that the documents executed by such attorney-in-fact on behalf of the
undersigned, pursuant to this Power of Attorney, shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in his or
her discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform all and every act and thing whatsoever requisite,
necessary, and proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming to all that such attorney-in-fact, or his or her
substitute or substitutes, shall lawfully do or cause to be done by virtue of
this Power of Attorney and the rights and powers herein granted.  The
undersigned acknowledges that no such attorney-in-fact, in serving in such
capacity at the request of the undersigned, is hereby assuming, nor is the
Company hereby assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Exchange Act or Section 5 of the Securities Act or Rule
144 promulgated under such Act.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, 5 and 144 with respect to
the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing delivered
to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 5th day of November, 2019.

/s/ Robert G. Ashe
Robert G. Ashe