Quotes from Donella H. Meadows

and if they have no hope of winning, could get frustrated enough to destroy the playing field.

If an eventual nine billion people all consumed materials at the rate of the average late-twentieth-century American, that would require an increase in worldwide steel production by a factor of five, copper by a factor of eight, and aluminum by a factor of nine.

After a session of working with a model, computer or mental, it's a good idea to step back for a moment and remember that it is not the "real world" we have been experiencing, but a representation that is "realistic" in some respects, "unrealistic" in others. The task is to find insight in the model from those features of the scenarios that seem "realistic.

Therefore the "real" system may not respond as forcefully or successfully as does the World3 system. The model's perfectly working market and smooth, successful technologies (with no surprising side effects) are also very optimistic.

There is a systematic tendency on the part of human beings to avoid accountability for their own decisions.

Dynamic systems studies usually are not designed to predict what will happen. Rather, they're designed to explore what would happen, if a number of driving factors unfold in a range of different ways.

Growth of what? For whom? At what cost? Paid by whom? What is the real need here, and what is the most direct and efficient way for those who have that need to satisfy it? How much is enough? What are the obligations to share?

Resilience is a measure of a system's ability to survive and persist within a variable environment. The opposite of resilience is brittleness or rigidity.

According to the competitive exclusion principle, if a reinforcing feedback loop rewards the winner of a competition with the means to win further competitions, the result will be the elimination of all but a few competitors. The rich get richer and the poor get poorer.

At any given time, the input that is most important to a system is the one that is most limiting.

Mental flexibility—the willingness to redraw boundaries, to notice that a system has shifted into a new mode, to see how to redesign structure—is a necessity when you live in a world of flexible systems.

Systems often have the property of self-organization—the ability to structure themselves, to create new structure, to learn, diversify, and complexify. Even complex forms of self-organization may arise from relatively simple organizing rules—or may not.

QUESTIONS FOR TESTING THE VALUE OF A MODEL Are the driving factors likely to unfold this way? If they did, would the system react this way? What is driving the driving factors?

My word processor has spell-check capability, which lets me add words that didn't originally come in its comprehensive dictionary. It's interesting to see what words I had to add when writing this book: feedback, throughput, overshoot, self-organization, sustainability.

I have yet to see any problem, however complicated, which, when looked at in the right way, did not become still more complicated. —POUL ANDERSON

most of what goes wrong in systems goes wrong because of biased, late, or missing information.

Hierarchies are brilliant systems inventions, not only because they give a system stability and resilience, but also because they reduce the amount of information that any part of the system has to keep track of.

The world peeps, squawks, bangs, and thunders at many frequencies all at once. What is a significant delay depends—usually—on which set of frequencies you're trying to understand.

There is yet one leverage point that is even higher than changing a paradigm. That is to keep oneself unattached in the arena of paradigms, to stay flexible, to realize that no paradigm is "true," that every one, including the one that sweetly shapes your own worldview, is a tremendously limited understanding of an immense and amazing universe that is far beyond human comprehension.

Carter also was trying to deal with a flood of illegal immigrants from Mexico. He suggested that nothing could be done about that immigration as long as there was a great gap in opportunity and living standards between the United States and Mexico. Rather than spending money on border guards and barriers, he said, we should spend money helping to build the Mexican economy, and we should continue to do so until the immigration stopped.

You can see some things through the lens of the human eye, other things through the lens of a microscope, others through the lens of a telescope, and still others through the lens of systems theory. Everything seen through each kind of lens is actually there. Each way of seeing allows our knowledge of the wondrous world in which we live to become a little more complete.

Pay Attention to What Is Important, Not Just What Is Quantifiable

Because we bump into reinforcing loops so often, it is handy to know this shortcut: The time it takes for an exponentially growing stock to double in size, the "doubling time," equals approximately 70 divided by the growth rate (expressed as a percentage). Example: If you put $100 in the bank at 7% interest per year, you will double your money in 10 years (70 ÷ 7 = 10). If you get only 5% interest, your money will take 14 years to double.

We live in an exaggerated present—we pay too much attention to recent experience and too little attention to the past, focusing on current events rather than long-term behavior.