If the gross national product is higher and the consumer psychology changes, then the supply of vegetables will increase substantially; If the gross national product does not rise, or if the supply of vegetables will increase substantially, then the minimum standard of living for urban residents will not be guaranteed; if the supply of vegetables increases substantially, then perhaps farmers' incomes will increase,or an increase in social welfare. In fact, the minimum standard of living for city dwellers is guaranteed.
The consumer psychology of the public has not changed can be inferred.