List of national legal systems
Common law is currently in practice in Ireland, most of the United Kingdom (England and Wales and Northern Ireland), Australia, New Zealand, Bangladesh, India (excluding Goa), Pakistan, South Africa, Canada (excluding Quebec), Hong Kong, the United States (on a state level excluding Louisiana), and many other places. In addition to these countries, several others have adapted the common law system into a mixed system. For example, Nigeria operates largely on a common law system, but incorporates religious law.
Legal origins theory
In a series of influential papers published between 1997 and 2008 (the first one being La Porta et al. (1997) and the last one being La Porta et al. (2008)), Rafael La Porta, Florencio Lopez-de-Silanes, Andrei Shleifer, and Robert Vishny exploited the exogenous assignment of these very different institutions and assumed that they have not been reformed later on to provide evidence consistent with the idea that common law is correlated with"(a) better investor protection, which in turn is associated with improved financial development […], (b) lighter government ownership and regulation, which are in turn associated with less corruption, better functioning labor markets, and smaller unofficial economies, and (c) less formalized and more independent judicial systems, which are in turn associated with more secure property rights and better contract enforcement " [La Porta et al. 2008, p. 298]. Operationally, the "legal origins" scholars assigned the majority of countries in the world to either the English-common law, the French-civil law, or one among the German, Scandinavian, and Socialist legal traditions and then they calculated correlations between these legal origins dummies and proxies for the aforementioned economic outcomes.