The latest NERI seminar, from Kieran McQuinn and Robert Kelly of the Central Bank, examined the relationship between unemployment and house prices and used this relationship to examine the impact on banking defaults / mortgage defaults of economic growth. Modelling a fiscal stimulus of €2b, they estimated that bank defaults would decrease by about €660m; a saving to the state in either reduced future bank capital injections or refunds from current capital provisions. Combined with the ESRI estimated multiplier effect, where the cost to the economy of €2b stimulus is just under €1.3b, the research points towards the real cost of an investment stimulus in Ireland today. Ignoring that this investment would be in beneficial projects which would in any event pay for themselves over time (generally these are examined over a 20 year time period), the short term cost would be about €350m for every €1bn of stimulus.
The slides from the (excellent and very interesting) presentation and the accompanying Central Bank research paper are available here.