Intuitively you think it must have a material impact on the cost of capital. For me it's the opposite. In the investment-grade markets over any 10-year rolling period in the last century, only 4% of investment-grade corporations become bankrupt. In the junk bond market, 26% become bankrupt. So the cost of capital and any change in the bankruptcy law relates only to that small percentage of companies who go bankrupt. By the time you take that into account for all the corporations as a whole, then the cost of capital is de minimis.
In the work I have done with the investment grade, 0.16% would be the average, based on the Moody's statistics for bankruptcy and the losses borne by bondholders in the bankruptcy's centre.