The economic history of the last half century offers two cases of serious international depressions in countries with an essential orientation toward… - Bertil Ohlin

It seems beyond doubt that the tariff policy pursued during the last half century has not raised the standard of living of the labouring classes. It is doubtful if agricultural duties increase the relative scarcity of manual labour compared with other factors, and they certainly raise the cost of living for the working classes. It is, however, true that manufacturing duties tend to depress the rent of farm land... It is on the whole not at all unlikely that the sum total of rent is reduced in countries with high manufacturing duties... In most countries, however, the sum of rents is small compared with the sum of wages to manual workers. Even a substantial reduction of the former brings only a slight increase in the latter.

Curiously enough, John Stuart Mill, although he must have been familiar with Longfield's writings, seems never to have touched upon this line of reasoning.

I started [in 1921] to write on the foundations of an approach to international trade theory that was to some extent new and for which I received the inspiration during a stroll on [the popular promenade] Unter den Linden in Berlin in 1920.