Earthquake weather Earthquake weather Earthquake weather is a type of weather popularly believed to precede earthquakes. Since ancient times, the notion that weather can somehow foreshadow coming seismic activity has been the topic of much discussion and debate. Geologist Russell Robinson has described "earthquake weather" as one of the most common pseudoscientific methods of predicting earthquakes. Aristotle proposed in the 4th century BC that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory led to a
Zero-profit condition Zero-profit condition In economic competition theory, the zero-profit condition describes the condition that occurs when an industry or type of business has an extremely low (near-zero) cost of entry. In this situation, many people tend to join the industry, seeing the opportunity to make money, until there is no more money to make (supply exceeds demand); the large amount of competition limits each person's share of the market, as well as their ability to pursue a large profit margin. This would represent a situation of almost perfect competition. For instance, despite the real estate boom of the mid-2000s, the incomes