remove the commented text

Author: HumphreyYang

lectures/tax_smooth.md

@@ -656,15 +656,4 @@ plt.plot(ξ1_arr, cost_grad)
 plt.ylabel('derivative of cost')
 plt.xlabel(r'$\phi$')
 plt.show()
-```
-
-<!-- ## Wrapping up the consumption-smoothing model
-
-The consumption-smoothing model of Milton Friedman {cite}`Friedman1956` and Robert Hall {cite}`Hall1978`) is a cornerstone of modern macro that has important ramifications for the size of the Keynesian  "fiscal policy multiplier" described briefly in
-QuantEcon lecture {doc}`geometric series <geom_series>`.  
-
-In particular,  it  **lowers** the government expenditure  multiplier relative to  one implied by
-the original Keynesian consumption function presented in {doc}`geometric series <geom_series>`.
-
-Friedman's   work opened the door to an enlightening literature on the aggregate consumption function and associated government expenditure  multipliers that
-remains  active today.   -->
+```