A large empirical literature finds that there is too little international trade and too much intranational trade to be rationalized by observed international trade costs, such as tariffs and transport costs. This paper investigates whether a model in which the nature of production can change in response to trade costs—a framework with multistage production—can better explain the home bias in trade. The calibrated model can explain about two-fifths of the Canada border effect, about two-and-one-half times that of a model with one production stage. The model also explains a significant fraction of Canada-US “back-and-forth,” or vertical specialization, trade.

International Trade and Business Cycles: Is Vertical Specialization the Missing Link? by M. Ayhan Kose and Kei-Mu Yi. Published in volume 91, issue 2, pages 371-375 of American Economic Review, May 2001

A common view is that cross-border vertical linkages played a key role in the 2008–2009 collapse of global trade. This paper presents two accounting results from a global input-output framework that shed light on this channel. We feed in observed changes in final demand and find that trade in final goods fell by twice as much as trade in intermediate goods. Nevertheless, intermediate goods account for more than two-fifths of the trade collapse. We also find that vertical specialization trade fell 13 percent, while value-added trade fell by 10 percent, because declines in demand were largest in highly vertically-specialized sectors.

Why Is Manufacturing Trade Rising Even as Manufacturing Output is Falling? by Raphael Bergoeing, Timothy J. Kehoe, Vanessa Strauss-Kahn and Kei-Mu Yi. Published in volume 94, issue 2, pages 134-138 of American Economic Review, May 2004