Confidence votes 20.3K. There are two basic types of submarine screws. (Screw is the proper term here as propeller is applied to small craft.) One of the screws is built for silence, and the other is built for speed. Screws built for speed typically have fewer blades and the blades are wider to grab more water as the screw spins in the water.
Economic Definition of assumption. Defined. Term assumption Definition: An initial condition or statement that sets the stage for an analysis by abstracting from the real world. Assumptions are important to economic theories and economic analysis. Some assumptions are used to simplify a complex analysis into more easily manageable parts.
However, the assumptions economists make have a huge effect on the world of economics and therefore world economies. One response to these assumptions that is popular among non-economists is to deride economists and call for their assumptions to be dumped. A great many people feel that viewing the economy as governed by self-interested utility maximisers as so unrealistic as to be useless. They say we should ditch it all and start afresh. Most of the key pillars of neo-classical economics have been debunked.