SIO stated that street prostitution in Copenhagen was overestimated by 1000 persons, attributing over reporting to an NGO, Reden, that works with women in prostitution, and the numbers of women that they had seen. Other data suggests that any over reporting would not be as large and even if so the number of persons in prostitution in total is many times larger in Denmark than in Sweden and Danish numbers on indoor prostitution were estimated at 3278. These numbers were mainly based on advertising, not Reden. Assuming 1415 is the number for outdoor prostitution in Denmark, that only amounts to a fourth of prostitution in Denmark. Therefore, it seems unlikely that street prostitution could be so significantly lower as SIO claims. However, whatever the numbers, the scientific question is whether this has anything to do with the sex purchase law or, rather, reflects historical patterns and cultural attitudes.