Auctioning the right to come to Australia could raise $35,000 to $45,000 per immigrant, enough to boost the budget by $7.6 billion per year, a Productivity Commission analysis has found.

But the commission has found against the idea in a draft report to be released on Friday, saying that stripping the government of the right to decide who comes to Australia could lead to unpredictable changes in the immigration program and cost it community support.

The Coalition asked the Productivity Commission to examine the idea as part of a deal struck with Liberal Democrat Senator David Leyonhjelm in return for his vote on the reintroduction of temporary protection visas for asylum seekers.

The report finds that immigrants willing to bid to come to Australia are more likely to be older and wealthier than other immigrants, and as a result less likely to contribute to the economy.