Interest rates to national income
In structural parameters. A model may pretend various exogenous variables, in addition to those variables may conform to relieve oneself various responses by economic variables. Methodological uses of models add investigation, theorizing, and fitting theories to a world.
One of the major problems addressed by economic models has been apprehension economic growth. An early try to render a technique to approach this came from the French physiocratic school in the Eighteenth century. Among these economists, François Quesnay was asked particularly for his development and ownership of managers he called Tableaux économiques. These structures do in fact been interpreted in more innovative terminology as a Leontiev model, see the Phillips mention below.
All through the 18th century that is, well before the founding of sophisticated political economy, conventionally marked by Adam Smith's 1776 Mensura Sortis, where he presented what would today be called "logarithmic service of money" and applied it to gambling and insurance problems, including a result of the paradoxical Saint Petersburg problem. any of these developments were summarized by Laplace in his Analytical opinion of Probabilities 1812. Clearly, by the time David Ricardo came along he had a lot of well-established math to draw from.