"Efficiency is doing things right; effectiveness is doing the right things” has been credited to management consultant and author Peter Drucker (1909-2005), who said something like this in 1960s lectures and in his book, The Effective Executive (1967). “Managers do things right; leaders do the right thing” is credited to authors Warren G. Bennis and Burt Nanus, who wrote this in their book, Leaders: The Strategies for Taking Charge (1985).
Wikipedia: Peter Drucker
Peter Ferdinand Drucker (November 19, 1909 – November 11, 2005) was an influential writer, management consultant, and self-described “social ecologist.”
But the theme of his (Peter Drucker—ed.) address, to both morning and afternoon sessions, was “effectiveness”—doing the right things as opposed to doing things right. It was a common failure of most businesses, he said, that they dissipated their resources “doing a little more effectively what should not be done at all”.
OCLC WorldCat record
The effective executive
Author: Peter F Drucker
Publisher: New York : Harper & Row, 
Edition/Format: Book : English : [1st ed.
Summary: Analyzes the practices the executive must master in order to be truly effective.
10 September 1967, Sunday Herald (Provo, UT), “BYU Pre-School Event: Officials Counsel Student Leaders,” pg. 12A, cols. 2-3:
Other speakers were Stephen R. Covey, assistant to the president in charge of university relations, who reminded the students that “efficiency is doing things right and effectiveness is doing the right things,” ...
The Trusteeship of Colleges and Universities
By Morton A. Rauh
New York, NY: McGraw-Hill
Peter Drucker makes the point well when he says, “Efficiency, which is doing things right ... is very important. But doing the right things — effectiveness — is a great deal more important. There is joy neither in heaven nor on earth in an engineering department which with great dispatch and precision turns out beautiful blueprints for the wrong product.”
A manual for profit improvement and growth
By Joseph Eisenberg
New York, NY: McGraw-Hill
Peter Drucker has an interesting play on words that applies to this: he defines efficiency as “doing things right”; effectiveness, as “doing the right things.
Marketing for Managers
By Frederick E. Webster
New York, NY: Harper & Row
Someone once defined strategic decisions as those concerned with “doing the right things,” as contrasted with operating decisions, which are concerned with “doing things right.”
Fifteen key concepts for managerial success
By the Harvard Business Review.
Cambridge, MA: President and Fellows of Harvard College
It is fundamentally the confusion between effectiveness and efficiency that stands between doing the right things and doing things right. There is surely nothing quite so useless as doing with great efficiency what should not be done at all.
OCLC WorldCat record
Leaders strategies for taking charge : the strategies of taking charge
Author: Warren G Bennis; Burt Nanus
Publisher: New York : Harper & Row, ©1985.
Edition/Format: Book : English
Community, Technical, and Junior College Journal
In Leaders: The Strategies for Taking Charge, authors Warren Bennis and Burt Nanus state: “Managers do things right; leaders do the right thing.”
The World of Business
By Gerald H. Graham
Reading, MA: Addison-Wesley Pub. Co.
Do we have, as Bennis and others suggest, a shortage of effective leadership in our corporations? Whereas managers focus on doing things right, leaders focus on doing the right things.
28 November 1988, The Daily Herald (Chicago, IL), “Cryptoquote,” sec. 5, pg. 3, col. 2:
EFFICIENCY IS CONCERNED WITH DOING THINGS RIGHT. EFFECTIVENESS IS DOING THE RIGHT THINGS.—PETER R. DRUCKER.
Administrative Leadership in the Social Services:
The next challenge
By Yeheskel Hasenfeld
New York, NY: Haworth Press
The managers focus on efficiency by “doing things right.” The leaders focus on effectiveness by “doing the right things.”
Google News Archive
30 June 1989, The Sentinel (Rochester, IN), “Suddenly, he learns a truth” by C. W. Gusewelle, pg. 4, col. 6:
“A manager,” he said, “is only concerned with doing things right. A leader is concerned with doing the right things.” Managers fret with the details. Leaders have a vision, and inspire others to share it.
The Seven Habits of Highly Effective People:
Restoring the character ethic
By Stephen R. Covey
New York, NY: Simon & Schuster
In the words of both Peter Drucker and Warren Bennis, “Management is doing things right; leadership is doing the right things.”
25 September 1991, Daily Herald (Chicago, IL), “People are real estate success key,” sec. 1, pg. 2,col. 2:
“Doing things right is leadership, doing the right thing is management.”
(David A. Baker of ERA Real Estate North Central Division—ed.)
New York City • Work/Businesses • (1) Comments • Monday, April 02, 2012 • Permalink
It’s amazing how the two sentences express an entirely different thought when the two words were just interchanged. Leadership entails not only doing the things right but also having the initiative to exceed what’s expected of you and your team.