In the representative economy model presented in Table 2.3, exports are assumed to be completely autonomous and fixed at 500 TL across all income levels. This demonstrates the assumption that a nation's export volume is determined by foreign income and preferences rather than domestic GDP.
According to the representative data in Table 2.3, every 1,000 TL increase in national income leads to a 100 TL increase in imports. This yields a calculated Marginal Propensity to Import (MPI) of 0.10, which determines the negative slope of the net export function.
In the graphical model of wealth changes (Figure 2.3), an increase in household wealth shifts the autonomous consumption level upward from 600 TL to 1,000 TL. This parallel shift of 400 TL demonstrates how non-income variables alter consumption behavior at every single level of income.
While the curves for C, C + I, and C + I + G are parallel because investments and government expenditures are autonomous, the final AE curve (C + I + G + NX) has a flatter slope. This is because the net export function has a negative slope due to the income-dependent nature of imports.
In the representative economy described in Table 3.1, when GDP is at 6,000 TL and planned aggregate expenditures are only 5,600 TL, firms experience an unplanned stock increase of 400 TL. This unplanned inventory investment forces firms to cut back production in the subsequent period.
Classical economists argued that the interest rate determined in the loanable funds market acts as the balancing mechanism that equates savings and investments. Any increase in household savings lowers the interest rate, which automatically stimulates an equal increase in business investments.
Because consumer expectations are subjective and highly difficult to observe directly, policy-makers periodically conduct structured expectation surveys. These surveys allow economists to monitor shifts in consumer sentiment and predict autonomous changes in consumption and saving functions.