We propose a normative theory of the number of representatives based on a model of a representative democracy. We derive a formula giving the number of representatives as proportional to the square root of total population. Simple tests of the formula on a sample of a 100 countries yield good results. We then discuss the appropriateness of the number of representatives in some countries. It seems that the United States has too few representatives, while France and Italy have too many. The excess number of representatives matters: it is positively correlated with indicators of red tape and barriers to entrepreneurship.