Exhibit 24.1

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned, a director of MSCI Inc., does hereby appoint Henry A. Fernandez and David M. Obstler, and each of them, his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this report on Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agents full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, the undersigned has signed this Power of Attorney on and as of the 25th day of January, 2011.

/s/ Benjamin duPont

Printed Name: Benjamin duPont

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned, a director of MSCI Inc., does hereby appoint Henry A. Fernandez and David M. Obstler, and each of them, his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this report on Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agents full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, the undersigned has signed this Power of Attorney on and as of the 24th day of January, 2011.

/s/ Alice Handy

Printed Name: Alice Handy

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned, a director of MSCI Inc., does hereby appoint Henry A. Fernandez and David M. Obstler, and each of them, his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this report on Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agents full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, the undersigned has signed this Power of Attorney on and as of the 24th day of January, 2011.

/s/ Catherine Kinney

Printed Name: Catherine Kinney

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned, a director of MSCI Inc., does hereby appoint Henry A. Fernandez and David M. Obstler, and each of them, his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this report on Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agents full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, the undersigned has signed this Power of Attorney on and as of the 24th day of January, 2011.

/s/ Scott Sipprelle

Printed Name: Scott Sipprelle

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that the undersigned, a director of MSCI Inc., does hereby appoint Henry A. Fernandez and David M. Obstler, and each of them, his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this report on Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agents full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or their or his or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, the undersigned has signed this Power of Attorney on and as of the 26th day of January, 2011.

/s/ Patrick Tierney

Printed Name: Patrick Tierney