propensitypro·pen·si·ty /prəˈpensəti/ noun (plural propensities) [countableC]1a tendency to behave in a particular wayThe plastic-bodied car’s propensity to catch fire killed demand.
2marginal propensity to consumeECONOMICS the relationship between a change in people’s income and the change in the amount that they spend on goodsThe marginal propensity to consume is 0.8, because for every £10 million rise in income, consumption rises by £8 million, and the marginal propensity to save is 0.2.
3marginal propensity to importECONOMICS the relationship between a change in people’s income in a country, and the change in the amount that the country importsThe marginal propensity to import is 0.2, so that for every £10 million rise in income, spending on imports rises by £2 million.
4marginal propensity to saveECONOMICS when there is a change in people’s income, the change in the amount that they save in relation to the amount they spend