A government research paper has shown mining has increased, but overall resource investment is still well down.

The New South Wales Government-commissioned research say expenditure in areas including the Hunter Valley is increasing.

Exploration rose 14 per cent in the last year, but it is still 37 per cent down on figures for September 2011.

The figures come as hundreds of Hunter Valley mine workers deal with the announcement that their jobs will be cut. The report says the decline in mining investment has restricted broader economic growth.

The report says that decline will continue, gathering speed as large mining projects reach completion.

Aside from some more spending on exploration, the report is in line with nationwide stats, which show investment in the mining sector has been slowing for several years.

Money spent in the mining sector across Australia has dropped 54 per cent from 2012 figures.