A very different reason for trade is technical innovation. Manufactured goods
often require specialist investment and expertise. Once a particular company or
country has become established in this area, it is difficult for others to build up
sufficient volume of sales to break into that market. In the nineteenth century
Britain developed mechanized textile manufacturing, and for some years gained a
great benefit from this. Eventually other countries caught up. Today technical
advance is continuous. The manufacture of medical equipment, the production of
a particular type of rubber belt drive, or the manufacture of complex products
such as cruise ships and aircraft are all examples where one country has developed
a competitive advantage based on technical innovation and is protected by barriers
such as the high cost of entry. In the case of particular inventions the manufacturing
rights may even be covered by a patent.