"The term cobra effect originated in an anecdote set at the time of British rule of colonial India. The British government was concerned about the number of venomous cobra snakes in Delhi. The government therefore offered bounty for every dead cobra. Initially this was a successful strategy as large numbers of snakes were killed for the reward. Eventually, however, enterprising people began to breed cobras for the income. When the government became aware of this, the reward program was scrapped, causing the cobra breeders to set the now-worthless snakes free. As a result, the wild cobra population further increased. The apparent solution for the problem made the situation even worse."
https://www.atlasobscura.com/articles/hanoi-rat-massacre-190...
If the city were serious about getting rid of rats they'd provide incentives for or otherwise subsidize behavior that helps solve the problem (which is very different from penalizing behavior that doesn't, I know those two often get confused around here). I'm not seeing any evidence of such based on this article which leads me to believe this is probably not an effective use of available resources. Efficient exterminators and other silver bullets don't usually do a good job solving big problems in the long term.