The PNDT Act was passed over twenty years ago with the intention of reducing female foeticide and improving the sex ratio at birth. It's high time we evaluated the effect of this law scientifically and critically.
The hypothesis behind the PNDT Act was that it was the misuse of ultrasound scanning which was causing the sex ratio to decline . This is why the PNDT Act empowers government officials to seal machines which are being misused . Once these machines are sealed, one would then expect that the sex ratio in that locality would improve in the following year - after all, this is the objective of the Act. Since illegal ultrasound scanning has been stopped thanks to the Act in that area, female fetuses would no longer be illegally terminated in that region, and more girls would be born in the subsequent year .
Now I understand that patients can travel from one area to another, but we can divide the country into well-defined areas, and it is reasonable to assume that if the PNDT Act is effective ,then the improvement of the sex ratio in any given area would be proportional to the number of machines seized in that area .
Because there is so much variation in how the Act has been implemented across the country by different local Appropriate Authorities , we now have enough natural experiments to be able to crunch this data intelligently. In order to study the impact of the PNDT Act, it would be interesting to see if there is any correlation between the number of ultrasound machines seized , and the sex ratio in the following year in well-defined geographical areas. If there is, this means we are on the right track. If there isn't, then we need to accept the fact that the basic premise on which the Act is based maybe wrong, and look for more effective measures to correct the sex ratio.
An unbiased social science researcher needs to look at this unemotionally and dispassionately to answer this important question.