Reasons for colonizing

Making a colony to harvest/mine/manufacture something is the most common
reason in SF, followed closely perhaps by fleeing something else to
establish the "Promised Land." In general terms, Mankind spreading out
in search of new land is another (generally downplayed) reason. 

In David Drake's "Redliners" the driving force behind colonization is an
intersteller war. The Terran government is aggressively pushing new
colonies without regard for whether or not it is profitable; they want
to spread Mankind out more. Entire apartment buildings are selected
(apparently at random), and the tenants just shuffled off to a new
planet to sink or swim.
Assuming they swam, they would certainly be interested in building up
internal trade/production and external trade, both. 

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Edward Lipsett
Intercom, Ltd.
Fukuoka, Japan
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