The most probable cause of excess supply is that the suppliers cannot perfectly predict the market (unpredictable events, which leads to changes of supply or demand). Even perfect screening of market is not possible. Another situation which lead to excess supply is
nominal rigidity, which is when suppliers are not able to quickly adapt to new situations. Suppliers have large stocks of goods and they cannot sell it with old price all. They cannot usually immediately change volume of production, especially if production process is really long. Here are some examples of why demand may decline and thus excess supply is created: • financial, economic crisis – people are scared and thus they spend less money and it automatically deepens the crisis • deflation – people think that they will be able to buy more for the same money in the future (deferred consumption) and thus it causes probably short term excess supply • products are forgotten quickly or they quickly become unpopular so the demand drop in the months or weeks • price control (price floor) – when the government interrupts market forces by imposing a price minimum above the equilibrium, excess supply is created Here are some examples of why supply may raise and thus excess supply emerge: • weather – for example excellent weather results in excellent harvests or sunny and windy days can lead to excess supply in electricity (typical for smaller regions in Australia) • cheap labor or free (autonomous) production • excessive production support (for example from government) • new technologies, which can be a product with old one's machine. We can see this problem in the world of mobile phones and many other devices, Lot of parts of this device is made up on the same production line with just setting machines on different settings. Those devices are sold at high prices because it is hot new so the demand on it is not so high on the other hand producer can make a lot of them. • Instant increase of production (usually hold for small monopoly markets with one manufacturer which upgrade his production line) • price wars • New entrants to the market with access to cheaper labor, energy, capital or land == Symptoms ==