Problem 10
Question
The Persson-Svensson model. (Persson and Svensson, 1989.) Suppose there are
two periods. Government policy will be controlled by different policymakers in
the two periods. The objective function of the period- \(t\) policymaker is
\(U+\alpha_{t}\left[V\left(G_{1}\right)+V\left(G_{2}\right)\right],\) where \(U\)
is citizens' utility from their private consumption; \(\alpha_{t}\) is the
weight that the period- \(t\) policymaker puts on public consumption; \(G_{t}\) is
public consumption in period \(t ;\) and \(V\) ( \(\bullet\) ) satisfies
\(V^{\prime}(\bullet)>0, V^{\prime \prime}(\bullet)<0 .\) Private utility, \(U,\)
is given by \(U=W-C\left(T_{1}\right)-C\left(T_{2}\right)\) where \(W\) is the
endowment; \(T_{t}\) is taxes in period \(t ;\) and \(C(\bullet),\) the cost of
raising revenue, satisfies \(C^{\prime}(\bullet) \geq 1, C^{\prime
\prime}(\bullet)>0 .\) All government debt must be paid off at the end of
period \(2 .\) This implies \(T_{2}=G_{2}+D,\) where \(D=G_{1}-T_{1}\) is the amount
of government debt issued in period 1 and where the interest rate is assumed
to equal zero.
(a) Find the first-order condition for the period- 2 policymaker's choice of
\(G_{2}\) given \(D .\) (Note: Throughout, assume that the solutions to the
policymakers' maximization problems are interior.
(b) How does a change in \(D\) affect \(G_{2}\) ?
(c) Think of the period- 1 policymaker as choosing \(G_{1}\) and \(D\). Find the
firstorder condition for his or her choice of \(D\)
(d) Show that if \(\alpha_{1}\) is less than \(\alpha_{2}\), the equilibrium
involves inefficiently low taxation in period 1 relative to tax-smoothing
(that is, that it has \(\left.T_{1}
Step-by-Step Solution
VerifiedKey Concepts
Fiscal Policy
- Policymakers in period 1 and period 2 apply fiscal policy to allocate resources efficiently between public and private sectors.
- The weight given to public consumption, represented by \( \alpha_{t} \), varies between the two periods, highlighting differing priorities in fiscal policy goals.
Government Debt
- The debt must be repaid in the second period, dictating future tax levels.
- Higher debt leads to increased future taxes as it aligns with the condition \((T_2 = G_2 + D)\).
- This can influence economic decisions like consumption and investment, affecting overall economic growth.
Utility Maximization
- In the exercise, policymakers try to optimize citizens' utility through fiscal policy decisions.
- The objective functions include terms for citizens' private utility \(U\) and public utility through government spending \(V(G)\).
- The first-order conditions derived in the solution define the precise amounts of \(G_2\) and \(D\) that maximize utility across periods.
Tax Smoothing
- The problem illustrates a deviation from tax smoothing, particularly when \( \alpha_1 < \alpha_2 \), resulting in lower taxation in the first period.
- A tax smoothing approach would imply \(T_1 = T_2\), maintaining consistent tax rates over periods, thus avoiding abrupt fiscal changes.
- The deviation occurs because the period-1 policymaker's emphasis on current consumption exceeds future consumption benefits.