The Central Bank of Ireland late last year unveiled a set of proposals aimed at cooling Irish property markets, including the controversial caps on LTV ratios on new mortgages. And this generated loads of controversy, shrill cries about the cooling effect of caps on property development and even speculations that the caps will put a boot into rapidly rising (Dublin) property prices. In response, our heroic property agents unleashed a torrent of arguments about supply, demand, sparrows and larks - all propelling the property prices to new levels, 'despite' the CBI measures announced (see for example here: http://www.independent.ie/business/personal-finance/property-mortgages/property-prices-set-to-rise-despite-lending-cap-plan-30879087.html for a sample of property marketers exhortations on matters econometric).
But never, mind the above. Truth is, the measures announced by the CBI are genuinely, for good economic reasons, have low probability of actually having a serious impact on property prices. At least all real (as opposed to property agents' economists') evidence provides for such a conclusion.
A recent paper by Kuttner, Kenneth N. and Shim, Ilhyock, titled "Can Non-Interest Rate Policies Stabilise Housing Markets? Evidence from a Panel of 57 Economies" (BIS Working Paper No. 433: http://ssrn.com/abstract=2397680) used data from 57 countries over the period spanning more than three decades, to investigatee "the effectiveness of nine non-interest rate policy tools, including macro-prudential measures, in stabilising house prices and housing credit."
The authors found that "in conventional panel regressions, housing credit growth is significantly affected by changes in the maximum debt-service-to-income (DSTI) ratio, the maximum loan-to-value ratio, limits on exposure to the housing sector and housing-related taxes. But only the DSTI ratio limit has a significant effect on housing credit growth when we use mean group and panel event study methods. Among the policies considered, a change in housing-related taxes is the only policy tool with a discernible impact on house price appreciation."
On DSTI finding, the authors estimate that setting a maximum DSTI ratio as the policy tool allows for a typical policy-related tightening, "slowing housing credit growth by roughly 4 to 7 percentage points over the following four quarters." In addition, on tax effectiveness, the authors found that while "an increase in housing-related taxes can slow the growth of house prices", this result is "sensitive to the choice of econometric method" used in model estimation.
Finally, on CBI-favoured LTV limits: "Of the two policies targeted at the demand side of the market, the evidence indicates that reductions in the maximum LTV ratio do less to slow credit growth than lowering the maximum DSTI ratio does. This may be because during housing booms, rising prices increase the amount that can be borrowed, partially or wholly offsetting any tightening of the LTV ratio."
In other words, once prices are rising, LTV caps are not terribly effective in controlling house price inflation.