Before revision:  This condition is stronger than the corresponding condition 1+2>1/2 for Holder classes of functions}  .
After revision:  This condition is stronger than the corresponding condition 1+2>1/2 for Holder classes of functions} approximately sparse regression. Such objects include a wide variety of interesting parameters such as the covariance between two regression residuals, a coefficient of a partially linear model, an average derivative, and the average treatment effect. We give lower bounds on the convergence rate of estimators of such objects and find that these bounds are substantially larger than in a low dimensional, semiparametric setting .