Title: Chapter 11 Ljungqvist and Sargent, Fiscal Policies in the non-stochastic growth model
1Chapter 11 Ljungqvist and Sargent, Fiscal
Policies in the non-stochastic growth model
2The model
- Preferences
- Resource constraint
- Investment identity
3Household problem
- Household present value budget constraint
- Some Household FONCs
- Government budget constraint
4User Cost of Capital
- Rewrite the household budget constraint as
- Resources are finite thus
5Deriving the user cost of capital
- Transversality condition imposes the following
restriction on allocations - User cost of capital formula
6Firms problem
- Perfectly Competitive Firms operating Constant
returns to scale production technology. -
7Government
- Government budget constraint
8Competitive Equilibrium
9A useful equilibrium condition
- Suppose initially that labor supply is inelastic
- Then we can derive
10Steps in computing a dynamic equilibrium
- Step one derive a steady-state equilibrium. A
steadystate equilibrium is a particular
competitive equilibrium in which all forcing
variables are constant. Note that 11.3.3
implies steady state capital stock is given by
11What about other variables?
- Use steadystate analogues of
12Finding the dynamic path
- Step 2 Solve for dynamic path (several different
ways to do this). - Need
- initial capital stock k0
- Terminal capital stock
13Finding dynamic path using shooting algorithm
- Given these objects the shooting algoritm
consists of the following steps
14Role of lumpsum taxes
- With lump-sum taxes we can implement the shooting
algorithm for given settings of the forcing
variables and then adjust the level of lumpsum
taxation to insure that the government budget
constraint is satisfied. - If lump-sum taxes are not available need to add
an additional loop to the shooting algorithm to
insure that government budget constraint is
satisifed.
15Solving more complicated systems
- For more complicated systems with money and or
other endogenous state variables it is more
convenient to solve for the equilibrium using a
nonlinear equation solver. -
16- As before need initial and terminal capital stock
k0,ks. - Need to solve
17Nonlinear equation solver
- Choose T large (100, 150 years)
- Assume that in period T the economy is in a
steadystate. - Dynare uses this approach. It implements a
version of Newtons algorithm to solve the system
of nonlinear equations.
18What are the effects of an increase in the
investment tax credit?
- Suppose the economy is initially in a
steadystate. - Investment tax credit is increased permanently in
period zero. - What is the initial response of capital,
consumption? - How do capital and consumption compare in the new
steadystate with their values in period zero?
19What are the effects of an anticipated increase
in the investment tax credit?
- Suppose the investment tax credit occurs in
period 10 instead of period 1. - In future periods the return in capital will be
high. - Takes time to accumulate capital.
- Makes sense to start accumulating capital now.
- What about consumption?
20PERMANENT INCREASE IN ?i
21TEMPORARY INCREASE IN ?i
22What are the effects of government policy on
allocations and prices?
- Ricardian Equivalence. If only lumpsum taxes are
used to finance government purchases the timing
of lumpsum taxes doesnt matter. The lumpsum tax
only enters the present value budget constraints.
It doesnt enter any of the marginal conditions.
(allocations and prices dont depend on the
timing of l.s. taxes)
23More effects of government policy on allocations
- When labor supply is inelastic the tax rate on
labor is not distorting. A constant consumption
tax is also not distorting. - If the consumption tax varies over time it is
distorting. - Taxes on capital and investment tax credits are
distorting even when constant and the timing of
these taxes matters.
24Generalizing the model to allow for a labor
supply decision.
- Endogenous labor supply adds an additional
equation
25Endogenous labor, steadystate and dynamics
- Steadystate
- Now solve for n, k and c.
- Dynamics Use previous two equations resource
constraint - to solve for ct, nt, kt1.
26Technological progress.
- Suppose that the production function is
- where
- No steadystate! Instead define a balanced growth
path with constant µ. - Existence of a balanced growth path imposes
restrictions on preferences when labor is
endogenous. See below.
27Solving for the dynamic competitive equilibrium
- Two strategies for proceeding.
- 1) leave the growth in.
- 2) Transform the economy and use the previous
notion of steady-state equilibrium. - The transformations with growing inelastic
labor input are -
-
28New dynamic equations for capital and consumption
29Restrictions on preferences with endogenous labor
- A period utility function of the following form
is consistent with balanced growth - Where ht is hours per worker! Assume aggregate
labor input is given by htnt - An example of a form of preferences that is not
consistent with balanced growth
30Where we are going next
- Applications
- Hayashi and Prescott (2002)
- Chen, Imrogoroglu, Imrohoroglu (2006).
- Homework 1 The effects of temporary and
permanent increases in government purchases on
output and interest rates. (Dynare).