VOL. 91 NO.
5
ACEMOGLU ET AL.:
THE
COLONIAL ORIGINS OF DEVELOPMENT 1387
ferences across countries? Let us once again com-
pare
two
"typical"
countries with
high
and
low
expropriation risk, Nigeria and Chile (these coun-
tries are typical for the IV regression in the sense
that they are practically on the regression line).
Our 2SLS estimate, 0.94, implies
that the 2.24
differences in expropriation risk between these
two countries should translate into 206 log point
(approximately 7-fold)
difference. In
practice,
the
presence of measurement error complicates this
interpretation, because some of the difference be-
tween
Nigeria
and
Chile's expropriation
index
may
reflect measurement error.
Therefore,
the
7-fold
difference is
an
upper
bound.
In
any case,
the estimates in Table
4
imply a substantial, but
not implausibly large, effect of institutional differ-
ences on
income per capita.
Colunm
(2)
shows that
adding
latitude does
not
change
the
relationship;
the
institutions
coefficient is now 1.00 with a standard error of
0.22.20
Remarkably,
the latitude variable
now
has the
"wrong" sign
and is
insignificant.
This
result
suggests
that
many previous
studies
may
have
found latitude to
be
a significant determi-
nant of economic performance because
it
is
correlated with institutions
(or
with the
exoge-
nous
component
of institutions caused
by early
colonial
experience).
Columns (3) and (4) document that our results
are not driven
by
the
Neo-Europes.
When we
exclude the
United
States, Canada, Australia,
and
New
Zealand,
the estimates remain
highly signif-
icant,
and in
fact increase
a little. For
example,
the
coefficient for
institutions
is now
1.28
(s.e.
=
0.36)
without the latitude
control,
and 1.21
(s.e.
=
0.35)
when we control for latitude. Columns
(5)
and
(6)
show
that
our results
are
also robust
to
dropping
all the African countries from our sam-
ple.
The
estimates without
Africa are somewhat
smaller,
but
also more
precise.
For
example,
the
coefficient
for institutions is
0.58
(s.e.
=
0.1)
without the latitude
control,
and still
0.58 (s.e.
=
0.12)
when we control for latitude.21
In columns (7) and (8), we add
continent dum-
mies to the regressions (for Africa,
Asia,
and
other,
with
America as the omitted
group).
The
addition of these dummies does
not
change
the
estimated effect of institutions,
and
the dummies
are
jointly insignificant
at the
5-percent
level,
though
the
dummy
for Asia is
significantly
differ-
ent from that of America. The fact that the African
dummy is insignificant suggests that
the
reason
why
African countries are
poorer
is not due to
cultural or
geographic factors,
but
mostly
ac-
counted for
by
the existence of worse institutions
in
Africa. Finally,
in
column
(9) we
repeat our
basic
regression using log
of
output per
worker
as
calculated
by
Hall and Jones
(1999).
The result is
veiy
close to our baseline result. The 2SLS
coef-
ficient is
0.98
instead
of 0.94
as in column
(1).22
This shows that whether we use income
per capita
or
output per worker
has
little effect
on our
results.
Overall,
the results in Table 4 show a
large
effect
of institutions on
economic performance.
In the
rest of the
paper,
we
investigate
the
robustness of
these results.
3
20
In 2SLS
estimation,
all covariates that are included in
the second
stage,
such
as latitude, are also included
in
the
first stage. When these first-stage effects are of no
major
significance
for
our argument,
we
do not report them
in
the
tables to save
space.
21
We should note at this point that
if
we limit the
sample
to
African
countries
only, the first-stage relationship
using
the protection against expropriation variable
becomes
con-
siderably weaker, and the 2SLS effect of institutions is no
longer significant. The 2SLS effect of institutions continue
to be significant when we use some (but not all) measures of
institutions. Therefore, we conclude that the relationship
between settler mortality and institutions is weaker within
Africa.
22
The results with other covariates are also very similar.
We repeated the same regressions using a variety of alter-
native measures of institutions, including constraints
on
the
executive from the Polity III data set, an index of law and
order tradition from Political Risk Services, a measure of
property rights from the Heritage Foundation, a measure
of
rule of law from the Fraser Institute, and the efficiency
of the
judiciary
from Business International. The results
and the
magnitudes
are
very
similar to those
reported
in
Table 4. We also obtained very similar
results
with the 1970
values for the constraints
on the
executive
and income
per
capita
in
1970, which
show
that the relationship between
institutional measures and income per capita holds across
time
periods. These results are reported
in
the
Appendix
of
the
working paper version,
and are also available from the
authors.
23
In
the working paper version, we also investigated the
robustness
of our
results
in
different subsamples
with
vary-
ing degrees of data quality and different methods
of
con-
structing the mortality
estimates. The results
change very
little,
for
example,
when we
use data only
from
Curtin
(1989),
Death
by Migration,
when we do not
assign
mor-
tality rates from neighboring disease environments, when