How much does it cost to process — perhaps we can use a gentler word like “consider” — the claims of asylum seekers offshore compared to doing it here?

The original “Pacific Solution” was estimated to have cost up to one billion dollars over five years, although that estimate remains unverified by Government documents. With an East Timor Solution in the offing (possibly, depending on which member of the East Timorese Government you talk to) how much would it cost to send a signal to asylum seekers not to come by boat and send a signal to swinging voters that the Government is tough enough on asylum seekers?

Costs are hard to pin down because processing facilities have fixed costs regardless of usage, and the average cost per detainee comes down as those costs are spread across more detainees. The cost of handling detainees, whether they’re kept at Villawood in Sydney or on Nauru, is therefore smaller per person if there are more of them.

And Immigration officials have traditionally been reluctant to provide a specific figure, instead directing enquiries to the Department’s Budget papers, annual reports and Senate estimates responses.

According to figures obtained by Greens Senator Sarah Hanson-Young, the Christmas Island facility cost just under $42.5m in the year to the end of August 2009.  The facility has $9.98m in fixed costs, incurred whether it’s used or not.

But the bulk of the costs, $32.5m, are incurred because of staff costs, interpreting services, health services and so on. Transport to and from Christmas Island requires expensive charter flights both for staff and for detainees when they are transferred to the mainland. At the end of August last year, Christmas Island had 541 detainees (however, it clearly would have processed a considerably larger number during the year).

We’ll have to wait until the next Senate Estimates hearings to get updated figures for Christmas Island and, perhaps, projections of what an East Timor facility would cost.

But according to the Department of Immigration’s responses to questions on notice, Christmas Island was considerably more expensive than onshore processing centre in 2008-09.  The largest facility, Villawood in Sydney, cost $32m, and held a maximum of 220 detainees (but, again, processed many more). The smallest centre, in Perth, held a maximum of 25 detainees during 2008-09, but cost $7.2m to operate.

Nevertheless, even the greatest economies of scale can’t overcome the fact that putting a processing centre in another country and having Australian Government officials working in it will be hideously expensive.