There’s invisible coordination behind the things we buy.

Comment “I, Trader” and we’ll send you the essay. Twenty-five years after 9/11, economist Peter C. Earle reflects on why the World Trade Center was such a powerful symbol of global commerce. Inside those towers, traders, brokers, bankers, insurers, analysts, and countless others helped coordinate the movement of goods, capital, information, and risk across the world. That observation leads Earle back to Leonard Read’s “I, Pencil.” A pencil requires cedar, graphite, brass, lacquer, labor, machinery, and transport. But those inputs must also find the right buyers, prices, places, and moments. Traders, arbitrageurs, warehouse operators, insurers, speculators, financiers, and other middlemen help perform that coordination across distances, currencies, and time. They discover prices, move goods toward higher-valued uses, carry inventories through time, transfer risks, bridge the interval between production and payment, and create workable links between strangers. Much of this work is easy to overlook because the middleman’s margin is visible while the costs he reduces are not.