Ecological rationality

Ecological rationality describes how a decision-making arrangement can work well when its rules fit the information, incentives, and relationships present in a particular setting. In the book, it is not a claim that people are invariably wise or that markets and groups always reach good outcomes. It is a way of asking how institutions can draw on what people know while limiting the distortions caused by imitation, fragmented information, and poorly designed rewards.

Rules, Information, and Group Judgment

Experiments by Angela Hung and Charles Plott show how the rules of a decision can change the quality of collective judgment. Students drew marbles from one of two urns: one contained twice as many light marbles as dark ones, and the other twice as many dark marbles as light ones. Each student privately saw the color drawn but publicly revealed only a guess about which urn was in use. In the ordinary version, students were paid for being individually correct. Because later participants could observe earlier guesses, they often followed the apparent consensus rather than their own evidence; information cascades began in 78 percent of trials.

Hung and Plott changed the incentive: students were paid according to whether the group’s majority answer was correct. To help the group, participants had reason to attend more to their own imperfect private information and less to previous guesses. An individual making a less accurate guess could therefore contribute to a more accurate collective answer. The group under this rule was significantly more accurate than the cascading groups. The result illustrates a central point of ecological rationality: good collective judgment is not achieved simply by asking individuals to imitate the choices already visible to them. The decision process must preserve the contribution of information that has not yet entered the group’s shared judgment.

Local Knowledge and Aggregation

The same problem appears in the organization of knowledge. Decentralization allows people close to a task to use specialized, place-specific experience that is difficult to summarize or transmit. Its strength is that it encourages independence and specialization while allowing people to coordinate and address difficult problems. Its weakness is that information discovered in one part of a system may never reach the rest. A crowd, corporation, or intelligence agency therefore faces a dual requirement: preserve local knowledge while finding a means to make it collectively useful.

The book contrasts centralization with aggregation in its discussion of American intelligence. After the September 11 attacks, congressional criticism focused on agencies’ failure to share information and on fragmented holdings that produced local snapshots rather than a coherent picture. Yet the proposed remedy need not be to place all judgment under a single traditional hierarchy. Linking agency databases could improve information flow while leaving agencies autonomous; the book notes that even two years after the attacks there was no unified watch list drawing on data from the intelligence community. The institutional challenge is to connect distributed knowledge without treating central command as a substitute for the knowledge held by people and agencies closer to particular problems.

Markets as an Aggregating Mechanism

The proposed FutureMAP program offered a more ambitious way to aggregate intelligence. Funded by the Defense Advanced Research Projects Agency, it included plans for small internal markets where analysts from different agencies, and perhaps a few outside experts, could trade contracts based on expectations about future events. Participants might use classified information, while the market’s incentives would favor accurate forecasts over pleasing a supervisor, agency, or political leadership. The intended advantage was not simply that analysts would make predictions, but that a market could bring together judgments otherwise separated by bureaucratic boundaries.

A second element, the Policy Analysis Market, was intended to be open to the public and focused on the Middle East. That feature made the proposal politically vulnerable: senators Ron Wyden and Byron Dorgan denounced it, and public reaction was hostile to the prospect that ordinary people might profit from terrible events. The book nevertheless argues that public participation could bring in information from people the intelligence community might not otherwise hear, including those deterred by patriotism, fear, or resentment. This argument concerns the market’s potential as an information-gathering device; it does not make forecasting accuracy equivalent to public legitimacy. A system can be designed to aggregate predictions and still raise serious questions about who participates, what is traded, and how the activity is understood by the public.

Incentives, Cooperation, and Institutional Fit

Ecological rationality also concerns incentives that shape behavior beyond prediction. Taxpaying, for example, is a cooperation problem: people benefit from public goods whether or not they personally contribute, so individual free riding can be attractive even though widespread evasion would undermine the goods everyone relies on. In 2001, the IRS audited only 0.5 percent of returns, making voluntary compliance important alongside legal enforcement. The book describes taxpayers as contingent consenters: willingness to pay depends partly on believing that others also pay and that evaders may be caught and punished. Cooperation is therefore sustained not by self-interest alone, but by reciprocal expectations about fairness and enforcement.

Experiments by Ernst Fehr and Simon Gächter make that tension concrete. Four players received twenty tokens each and played four rounds. A token placed in the public pot cost its contributor one token but gave 0.4 tokens to each member, so the group gained 1.6 tokens for every token contributed. If everyone contributed all their tokens, each would finish with thirty-two; if no one contributed, each would keep twenty. Yet the individually tempting strategy was to withhold contributions and benefit from others’ giving. Most players initially contributed about half their tokens, but contributions fell as participants saw others free riding; by the end, 70 to 80 percent were free riding. The rules made the social benefit of contribution clear, but did not by themselves prevent the erosion of cooperation.

The same attention to institutional fit clarifies why performance incentives can produce deceptive rather than useful information. In the early 1950s, sociologist Donald Roy worked as a lathe operator under a piece-rate system in which the rate rose at successive output thresholds and was eventually capped. Workers who produced too quickly risked having the thresholds raised, so they restricted their output and learned to manage the incentive system rather than maximize production. In corporations, bonus targets can prompt managers to lowball forecasts and manipulate results to meet expectations, sometimes at the expense of the future. Rules intended to motivate performance can thus reward concealment and gaming instead. Across these cases, ecological rationality asks not whether an incentive sounds efficient in abstraction, but what behavior it actually elicits under the conditions people face.

Democracy as Cooperation and Coordination

The book extends the distinction between good outcomes and good procedures to democracy. Critics of deliberative democracy question whether citizens have the time, patience, or inclination to reason about the common good. The underlying disagreement is about democracy’s purpose: whether it provides political involvement and stability, protects self-rule even when people make poor choices, or serves as a way to make intelligent decisions and discover truth. The book does not treat these purposes as interchangeable.

Its concluding argument is that democracy need not be a mechanism for solving cognitive problems or revealing a single, knowable public interest. Its strength lies instead in helping people manage the enduring problems of cooperation and coordination: how to live together and make that coexistence mutually beneficial. Democratic experience includes losing decisions and seeing opponents prevail, while accepting those outcomes on the expectation that valued institutions will survive and another opportunity will come. Compromise and the possibility of change make that acceptance possible. The decisions a democracy produces may not always demonstrate collective wisdom; the choice to make decisions democratically can still embody a practical form of collective intelligence.