Nowadays, the country and the black market are interdependent; what politics does not allow, the black market does.
The government needs to maintain order and does not allow monetary transactions. Now, there are many people with money but no grain tickets. Meanwhile, the black market even sells grain tickets, albeit at a much higher price than the market. However, the black market is not a charity and this price hike is understandable.
The continuous expansion of the black market is undoubtedly supported by government personnel. Otherwise, how could the black market always appear when needed, addressing the biggest issues for local residents?
Currently, it's the black market, not the state, that can provide ample grain. The government has no choice but to tacitly allow the growth of the black market, leading to varied developments of the black market in different provinces.