European history in the 17th, 18th, and 19th centuries was characterized by a succession of network-driven waves of innovation: the Scientific Revolution, the Enlightenment, and the Industrial Revolution. In each case, the sharing of novel ideas within networks of scholars and tinkerers produced powerful and mainly positive externalities, culminating in the decisive improvements in economic efficiency and then life expectancy experienced in the British Isles, Western Europe, and North America from the late 18th century. The network effects of trade and migration were especially powerful, as European merchants and settlers exploited falling transportation costs to export their ideas, as well as their techniques and goods, to the rest of the world. Thanks to those ideas, this was also an era of political revolutions. Ideas about liberty, equality, and fraternity crossed the Atlantic as rapidly as pirated technology from the cotton mills of Lancashire. Kings were toppled, aristocracies abolished, and churches dissolved or made to compete without the support of a state.
Yet the 19th century saw the triumph of hierarchies over the new networks. This was partly because hierarchical corporations—which began, let us remember, as state-sponsored monopolies like the East India Company—were as important in the spread of industrial capitalism as horizontally structured markets. Firms could reduce the transaction costs of the market as well as exploit economies of scale and scope. The railways, steamships, and telegraph cables that made possible the first age of globalization had owners.
He argues that networks once again have gained an advantage, but he backs away from forecasting the demise of hierarchical corporations and states.