EXHIBIT 10.10

March 10, 2016

Value Act Capital Management, L.P.

One Letterman Drive, Building D

4th Floor

San Francisco, CA 94129

Attention: General Counsel

Mr. D. Robert Hale

Ladies and Gentlemen:

We refer to the Cooperation Agreement dated January 29, 2015 among members of
the Value Act Group named therein, MSCI Inc., and D. Robert Hale, in his
individual capacity and as a member of the Value Act Group. Terms defined in the
Cooperation Agreement are used herein as therein defined.

You have informed us that the Value Act Group has reduced its ownership interest
in the Company to less than 6% of the outstanding shares of common stock of the
Company. As you know, under Section 1 of the Cooperation Agreement, in this
event, Mr. Hale is required to promptly offer to resign as Director, with it
being in the Board’s sole discretion whether to accept or reject such
resignation. In accordance with the Cooperation Agreement, Mr. Hale has offered
to resign from the Board.

After due consideration and in light of Mr. Hale’s valuable contributions to the
Board, the Board has requested that Mr. Hale continue as a member of the Board
and agree to be re-nominated for election as Director at the 2016 Annual
Meeting. We understand that Mr. Hale has graciously agreed to continue to serve
as a Director of the Board and to be re-nominated as Director. Accordingly, the
Board has determined not to accept Mr. Hale’s offer to resign from the Board,
and intends to re-nominate Mr. Hale for election as a Director at the 2016
Annual Meeting.

The Board intends to commence a search to find a replacement Director for Mr.
Hale on the Board. While any selection of a replacement Director shall be in the
Board’s sole discretion, the Board intends to consult with and seek the input of
Mr. Hale and the Value Act Group as it conducts this important search. At the
time the Board elects a new Director to replace Mr. Hale, Mr. Hale will promptly
offer to resign from the Board (and, if requested by the Company, promptly
deliver his written resignation to the Board (which shall provide for his
immediate resignation), it being understood that it shall be in the Board’s sole
discretion whether to accept or reject his resignation.

This letter agreement shall be governed by the laws of the State of Delaware and
may be executed in two or more counterparts either manually or by electronic or
digital signature (including by facsimile or electronic mail transmission).

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If the foregoing is acceptable to you, please countersign this letter agreement
to be effective as of the date first above written.

Very truly yours,

MSCI Inc.

 

  By:           /s/ Henry A. Fernandez                          Name: Henry A.
Fernandez                Title: Chairman, Chief Executive Officer and President

Accepted and Agreed as of the date first above written:

VALUEACT CAPITAL MANAGEMENT, L.P.

 

  By:           /s/ Charles C. Siu                                       Name:
Charles C. Siu                Title: Chief Financial Officer             /s/ D.
Robert Hale                      Name:  D. Robert Hale