and to the corresponding tax rates given by condition (27) in Lemma 1. □
In case (i), tiktii + ki > tj ktji , which gives α > 0. Consequently, implied by Lemma 2 state
i chooses td < tN . The decrease in si, following a marginal increase in ti , dominates the positive
effect of a lower labor tax rate. In case (ii), tiktii +ki < tj ktji and, thus, α < 0. Lemma 2 predicts
a tax rate choice td > tN . In case (v), tiktii + ki = tj ktji and, thus, α = 0. Consequently, td = tN .
To infer how the federal government sets labor taxes and transfers in a symmetric equilibrium,
we evaluate how the FMCPF and the marginal benefit of transfer spending have changed due
to an adjustment in capital taxes (relative to the Nash outcome). First observe that at a
symmetric allocation the FMCPF is independent of the level of td, ceteris paribus. The reason
is that in any symmetric equilibrium capital employment is ki = к which yields an identical
labor demand across regimes. Also, for a given τ, labor supply is unchanged - see (1). Thus,
equilibrium employment behavior is independent of the level of capital taxes once symmetrically
chosen. Furthermore, given s = sN , b0(g) T b0(gN) if td S tN . Following the federal first-order
condition (11) and assumption (A), the federal government will choose τd T τN if td S tN .
Since the federal government operates on the upward-sloping part of the federal tax revenue
curve (0 > ηi > -1 - see (11)), sd T sN if and only if τd T τN which completes the proof of
Proposition 3.
References
[1] Akai, N. and M. Sato, 2005, Decentralized leadership meets soft budget, CIRJE Discussion
Paper, vol. 391 (F-series), Tokyo.
[2] Becker, G.S., 1981, A treatise on the family, Harvard University Press, Cambridge, MA.
[3] Bernheim, B. and M. Whinston, 1986, Common agency, Econometrica 54, 923-942.
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