加藤賢悟（東京大学大学院経済学研究科）
	On the degrees of freedom in the shrinkage estimation
		We study the degrees of freedom in the shrikage estimation of the regression coefficients. Generalizing the idea of the Lasso, we consider the problem of estimating the coefficients by the projection of the OLS estimator onto a closed convex set. Then an unbiased estimator of the degrees of freedom is derived in terms of geometric quantities under a smoothness condition on the boundary of the closed convex set. As an application, we obtain a $C_p$ type criterion and AIC for selecting the tunig parameter.