The Ministry of Agriculture decreed that sparrows were a menace to crops and should be exterminated.
When this was done, hoards of insects that the sparrows would have eaten descended on the harvest and began to ravage the crops, whereupon the Ministry of Agriculture came up with the idea of costly pesticides.
The pesticides made the food expensive. They also made it a hazard to health. Too late it was discovered that it was the sparrows who, through feeding on the crops, managed to keep the food wholesome and inexpensive.
Before rushing towards what you might think would be a better solution, consider what is already in place.