An action, or anticipated action, by one person will change the behavior of other people in the present period

From Doing Bad by Doing Good: Why Humanitarian Action Fails by Christopher J. Coyne. Page 149. Three key implications emerge from an appreciation of systems-type thinking.

Second, people behave strategically, which means that an action, or anticipated action, by one person will change the behavior of other people in the present period. It turns out that other actors within the system
are not passive responders who can be moved and shifted as desired as if they were unresponsive pieces on a chess board. This insight was evident to one of the earliest and most famous humanitarians, Florence Nightingale, who warned that voluntary humanitarian efforts during war lowered the cost faced by warring governments, suggesting that conflicts would be longer and more intense when humanitarian assistance was offered. According to Nightingale’s logic, governments would respond to the benevolent motivations of humanitarians by engaging in more violence, which ran counter to the very principles held by humanitarians.

The fact that people respond strategically to external interventions may appear obvious, but a review of state-led humanitarian actions indicates that efforts to help those in need are often conceived and designed as if the intended recipients, and other actors in the system, are passive and nonstrategic in their behaviors.23 To provide a basic example of the neglect of this dynamic, consider trash collection in Iraq during the U.S. occupation, which many would consider to be a relatively simple technological problem with a straightforward solution. The accumulation of trash became a major problem in many parts of Iraq and created security concerns as members of the U.S. military worried that piles of trash would be used as cover for roadside bombs, also known as improvised explosive devises (IEDs). In response, the U.S. military paid Iraqis an above-average wage (even compared to what skilled workers earned) to collect trash. Iraqis responded by shifting their efforts from productive activities to finding and collecting additional trash so that they could receive the higher wage. In addition to increasing the overall amount of trash, this initiative undermined other efforts to encourage local entrepreneurship and business activity by raising the payoff to collecting trash.