We explore how firms grow by adding products. In contrast to most earlier work on the topic, our conceptual and empirical framework allows for separate treatment of product innovation (vertical differentiation) and diversification (horizontal differentiation). The market context is Japan’s...

During the Industrial Revolution technological progress and innovation became the main drivers of economic growth. But why was Britain the technological leader? We argue that one hitherto little recognized British advantage was the supply of highly skilled, mechanically able craftsmen who were...

At some point in the first half of the 19th century per capita GDP in the United Kingdom and the United States began to grow at something like one to two percent per year and have continued to do so up to the present. Now incomes in many economies routinely grow at 2 percent per year and some...

For two decades, the consensus explanation of the British Industrial Revolution has placed technological change and the supply side at center stage, affording little or no role for demand or overseas trade. Recently, alternative explanations have placed an emphasis on the importance of trade...

The rise in national industry concentration in the US between 1977 and 2013 is driven by a new industrial revolution in three broad non-traded sectors: services, retail, and wholesale. Sectors where national concentration is rising have increased their share of employment, and the expansion is...

Mortality was extremely high in the industrial cities of the 19th century, but little is known about the role played by pollution in generating this pattern, due largely to a lack of direct pollution measures. I overcome this problem by combining data on the local composition of industries in...

Many previous studies of the role of trade during the British Industrial Revolution have found little or no role for trade in explaining British living standards or growth rates. We construct a three-region model of the world in which Britain trades with North America and the rest of the world,...