Consider the following production possibilities frontier model for an economy that produces only two goods: barley and tablets. Which of the following is true regarding this economic model? The fact that there are only two goods produced in this theoretical economy, when, in reality, economies produce many more types of goods, means this model is generally useless. This PPF is not an economic model. In order to construct such a model, an economist would need real life data regarding countries that only produce two goods. The fact that there are only two goods produced in this theoretical economy is a simplifying assumption that still allows economists to demonstrate key economic concepts.