The purpose of life tables is to describe the mortality behav
iour of particular groups. The
construction of general life tables is based on death statis
tics and census figures of resident
populations under the hypothesis of closed demographic sys
tem. Among other assumptions, this
hypothesis implicitly assumes that entries (immigrants) a
nd exits (emigrants) of the population
are usually not significant (being almost of the same magnitu
de for each age compensating each
other). This paper theoretically extends the classical sol
ution to open demographic systems and
studies the impact of this hypothesis in constructing a life
table. In particular, using the data of
residential variations made available to the public by the S
panish National Statistical Office (INE,
Instituto Nacional de Estad
́
ıstica) to approximate migratory flows, we introduce in the p
rocess of
constructing a life table these flows and compare, before and
after graduation, the crude mortality
rates and the adjusted death probabilities obtained when mi
gratory flows are, and are not, taken
into accountPeer Reviewe
