To illustrate, if preference heterogeneity is limited, civil law is more technologically efficient being unbiased as common law but also certain. If preferences are sufficiently diverse instead, the distance between the biased civil law and the technologically efficient legal rule, which is the social optimal rule that will prevail in a perfectly homogenous society, becomes wider the higher preference heterogeneity is and the lower the quality of the political process is. Thus, civil law loses its technological primacy when preferences are sufficiently diverse and/or the political institutions are sufficiently inefficient (Guerriero, 2016b). Consistent with this prediction, a proxy for preference and, in particular, genetic diversity interacted with a measure of the degree to which the transplant legal system in 2000 was nearer to a perfect common law tradition has a positive and significant impact on the stock market development, the extent of private credit, and the employment level.name=":7" /> The estimates also imply that reforms towards a pure common law tradition in developing transplants with smaller than average preference heterogeneity will significantly brake stock market development and the extent of private credit, whereas reforms towards a pure common law tradition in developing transplants with larger than average preference heterogeneity will significantly foster stock market development. Finally, the two legal traditions fare equally well when compared with self-reported managers’ beliefs on how much the legal system is able to hit its efficiency targets and their satisfaction with the law.[2 This last patterns squares with the idea that legal traditions have a tendency towards optimality and so should not differ when compared through a proxy for social welfare. "This evidence delivers conclusions quite different from those drawn by the legal origins project and raises several concerns for the recent waves of reforms that, inspired by the legal origins literature, have introduced in developing countries institutions typical of a pure common law legal tradition (World Bank, 2004). This is particularly worrisome nowadays given the increasing demand for regulation created by the recent global economic crisis" 2016, p. 16.