we consider the effectiveness of a general real land tax in taxing
betterment values. Second, we consider the effectiveness of an
incremental real land tax for the same purpose, reflecting Mill's
proposed tax. We relate this latter form to a direct capital gains tax.
As a general case, consider the purchase price of a plot of land at
the end of year i= 0 that is expected to pay the owner an annual after-
income-tax rental stream of Y
i
=Y in years i =1,…,∞. Rents may
reflect the imputed value of the property to the owner–occupier, or
may be the explicit contractual amount paid by a tenant to a landlord.
Let ‘r’ be the real interest rate, ‘t’ the land tax rate, and ‘k’ other net
costs or benefits associated with the land (expressed as a ratio of the
land value); r, and k are treated as known, fixed rates. When the tax
rate is t, the value of the property at the end of year i is denoted V
i
t
.
Extending the analysis of Oates and Schwab (2009), the purchase
price of the property at the end of year 0 is given by the discounted
value of future rents less tax and other payments:
V
t
0
= ∑
∞
i =1
Y
1+r
ðÞ
i
−∑
∞
i =1
kV
t
0
1+r
ðÞ
i
−∑
∞
i =1
tV
t
0
1+r
ðÞ
i
ð1Þ
From the solution of a discounted infinite sum:
V
t
0
=
Y
r
−
kV
t
0
r
−
tV
t
0
r
ð2Þ
Equating terms and solving for V
0
t
gives the purchase price:
V
t
0
=
Y
r + k + t
ð3Þ
For the first betterment tax alternative, assume that initially no land
tax is in place. The initial value of the plot is therefore: V
0
0
=Y/(r+k). A
public infrastructure project is then built that raises the annual real
rental stream to Y⁎ and an annual land tax at rate t is levied; the new plot
value becomes: V
⁎
0
=Y⁎ / (r+k+t). If the tax rate were set to capture all
value uplift from the project (so that V
⁎
0
=V
0
0
), it would be given by:
t =
r + kðÞY⁎−YðÞ
Y
ð4Þ
For example, if r = 0.05, k= 0.00, and (Y⁎ −Y) / Y=0.1, the
required tax rate is t = 0.005.
The present discounted value of the tax flow equals tV
⁎
0
/r. One
policy aim may be to set this value equal to the per property project
cost, P. The resulting tax rate becomes:
t =
rr+ kðÞ
Y⁎−rP
ð5Þ
To interpret Eq. (5), note that rP is the per property interest servicing
cost of the project. Consider a project with P=$10,000, r=0.05,
k=0.00 and let Y⁎ = $11,000 (=1.1×Y, where Y=$10,000); hence
rP=$500 and the BCR, defined as (Y*− Y)/rP, equals 2. The resulting
t≈0.0024. If, instead, P =$20,000 (hence BCR = 1), the required
t= 0.005, consistent with the full value uplift case. Generalising, the
project can be financed through a flat land tax and still leave some value
uplift for local landowners provided BCRN 1; if BCRb 1, full financing
through a flat land tax will lead to a decline in property values.
Now consider the second alternative in which only real incremen-
tal land value is taxed (at rate t). The value of a plot of land that
experiences an unexpected rise in land rents from Y to Y⁎ due to a new
infrastructure investment becomes:
V
0
⁎
=
Y
r + k
+
Y⁎−Y
r + k + t
ð6Þ
The first term on the right hand side of Eq. (6) is the land value
prior to the rise in rents which remains unaffected by the incremental
land tax. The second term reflects the rise in land value consequent on
the project; the tax is levied on this increment. Thus the present
discounted value of tax revenue is given by [t(Y⁎ −Y)] /[r(r+k + t)].
The tax rate required to finance a project with per property cost, P,
becomes:
t =
r + k
Y⁎−YðÞ= rP½−1
ð7Þ
Eq. (7) establishes that an incremental (real) land tax can fully
finance a project if and only if the BCRN 1. Even then the tax rate may
be ‘high.’ For instance, if we assume the same values for r, k, Y and Y⁎
as before but with P = $19,000 (BCR≈ 1.053), the result is t= 0.95. A
tax rate of less than unity requires BCRN 1 + r+k. If the BCR is
favourable, a more moderate incremental land tax rate can result; for
instance, with P = $5000 (BCR =4), t≈ 0.017. Realistically, therefore,
full financing of a project through an incremental (real) land tax may
be restricted to projects with high BCRs.
A real incremental land tax can be conceived as a replacement for a
tax on real capital gains on land. The latter option taxes the one-off
annual capital gain at rate c; by contrast, an incremental land tax
spreads the tax over time. We can equate the present discounted
revenue from an incremental land tax with the revenue from a capital
gains tax, as follows:
t =
r + kðÞc
1−cðÞ
ð8Þ
For instance (with r= 0.05 and k =0.00), instead of a capital gains
tax of 30%, an incremental land tax could be substituted with a rate of
2.14% p.a. Each approach would result in 30% of the real capital gain
being taxed (in present discounted value terms), with the same
present discounted revenues accruing to government. Cash-flows
from an incremental land value tax would differ from a capital gains
tax since the former would be spread over the indefinite future
whereas a ‘pure’ capital gains tax is due immediately (within one
year) of the capital gain being apparent. In many jurisdictions, cash-
flow concerns with regard to the taxpayer means that the capital gain
is only payable on realisation of the property, which creates lock-in
effects and other complications. These issues are much less problem-
atic in the case of an incremental land tax.
3. Conclusions
Provided that independent land valuations are performed on all
properties, a betterment tax can be levied to fund public infrastruc-
ture and amenity investments under certain circumstances. A flat rate
land tax is one possibility, but that option taxes pre-investment land
values unrelated to the specific investment. An alternative is an
incremental land tax that taxes only the uplift in values due to the
new infrastructure or amenity. The full project cost can be recovered
by the latter tax with a tax rate of less than 100% if the project's
BCRN 1 + r+k where r is the cost of capital and k is other costs
associated with ownership of the land (expressed as an annual rate).
Provided this latter condition is met, the project can be fully
financed from the incremental betterment tax while leaving some
value uplift available for local landowners. If a land tax is already in
existence, addition of a special betterment tax has virtually no
additional adm inis trat ive cost; in addition, the ability t o avoid
(or evade) the tax is virtually non-existent since the land is valued
by an independent agency and is available as collateral in cases of non-
payment of tax. Furthermore, use of a land tax has favourable
efficiency properties relative to other taxation or funding options.
A capital gains tax is another option an d we de monstrate the
55A. Coleman, A. Grimes / Economics Letters 109 (2010) 54–56