How can exogenous factors cause economic fluctuations (business cycles)?

The basic circular flow model between households and firms is given by:

$$Y = C + I$$

where $Y$ is income/output, $C$ is consumption, $I$ is investment.

Exogenous factors are variables outside the model, such as government spending $G$, exports $NX$, or shocks.

Extended model:

$$Y = C + I + G + NX$$

Consumption function: $C = c_0 + c(Y - T)$, where $c$ is marginal propensity to consume, $T$ taxes (exogenous).

Change in autonomous spending $\Delta A$ (exogenous, e.g., $\Delta G$, $\Delta I$), causes $\Delta Y = \frac{1}{1 - c} \Delta A$.

Substitute example: Suppose $\Delta G = 100$, $c = 0.8$.

Then multiplier $= \frac{1}{1 - 0.8} = 5$.

$\Delta Y = 5 \times 100 = 500$.

Positive exogenous shock (e.g., technology improvement increases $I$) leads to expansion (boom).

Negative shock (e.g., oil price hike reduces $NX$) leads to contraction (recession).

Simplify: Multiplier amplifies shocks, causing business cycle fluctuations around trend.

State-owned enterprises (SOEs) often rely on state banks (financial enterprises) for funding.

Relationship: Financial enterprises provide loans, but political interference leads to inefficient allocation (soft budget constraint).

Example: SOEs get bailouts, crowding out private firms.

Corruption (e.g., bribes for loans) misallocates credit to unproductive firms.

Effects on business/services employment:

• Reduces investment in viable businesses $\rightarrow$ lower output, fewer jobs.

• Increases non-performing loans $\rightarrow$ banking crisis $\rightarrow$ credit crunch.

Substitute: Suppose corruption rate $k$ reduces efficient investment by $kY$.

Then employment $L = \frac{Y}{APL}$ falls, where $APL$ average product of labor.

Final impact: Corruption reduces employment in business and services sectors by 10-20% in affected economies (empirical estimates).

Economic fluctuations amplified by multiplier; corruption cuts employment by misallocating credit.