 London's financial industry has boomed since the deregulation of British financial markets (the "Big Bang") in the 1980s under the Thatcher government — but has also become dominated by foreign companies, especially American investment banks, rather than British firms (a result opposite to the original intention of the reforms).The analogy is typically used to mark a debate over whether it matters if an industry is primarily domestically owned if easing of foreign ownership restrictions allows the economy to benefit from foreign investment and increased global competition.The phrase can be used positively to assert the economic success of liberal attitudes towards foreign ownership (and sometimes to emphasize that such attitudes promote a level playing field for domestic and foreign interests alike); or it can be used negatively to emphasize how these policies have eroded a nation's ability to produce globally leading domestic companies.