How can a food crisis be analysed using micro economics?

Question

What roles does the supply and demand curves play?

How about the long-run and short-run theories?

What about stuff like perfect competition, monopoly, etc... how do these apply.

Answer 1

If I'm not mistaken, usually a food crisis results because of a significant, sudden increase in price.  This would mean either a leftward shift of the supply curve, a rightward shift of the demand curve, or a combination of both.  In the short run, the price increases significantly to deal with the sudden shortage of food.  However, in the long-run (assuming the market was in equilibrium before), farmers will see that they can now earn profits and enter the market until supply increases so that price goes down and the market enters equilibrium.  

Perfect competition and monopoly apply to analyze the market conditions.  At lower income levels, the food market is probably most closely resembling perfect competition, since there are many buyers and sellers, and nobody really cares which farm their apples come from.  However, at higher income levels, it becomes more like monopolistic competition or oligopoly in the market for processed food (that's why the generic brand is often less desirable than the brand name.)  It is very difficult to have a monopoly in food, because besides the fact that the government would never allow it, there are too many substitutes for different types of food.  For example, if there's a monopoly on breakfast cereal and prices are too high, you can always substitute oatmeal.