Making informed decisions about model adequacy has been an outstanding issue for regression models with discrete outcomes. Standard assessment tools such outcomes (e.g., deviance residuals) often show a large discrepancy from the hypothesized pattern even under true and are not informative, especially when data highly binary). To fill this gap, we propose quasi-empirical residual distribution f...

We present a generic non-nested Monte Carlo procedure for computing true upper bounds for Bermudan products, given an approximation of the Snell envelope. The pleonastic “true” stresses that, by construction, the estimator is biased above the Snell envelope. The key idea is a regression estimator for the Doob martingale part of the approximative Snell envelope, which preserves the martingale pr...

Several fastidious lactic acid bacteria require a new growth factor, originally termed the Lactobacillus bulgartcu8 factor (LBF), for growth on synthetic media (Williams, Hoff-Jorgensen, and Snell, 1949; Kitay and Snell, 1950). Highly purified concentrates of this factor contained bound pantothenic acid, a finding that led to the discovery that LBF was apparently identical with the fragment of ...

Rogosa, Tittsler, and Geib (1947) reported that many strains of Lactobacilluss bulgaricus, Lactobacillus lactis, Lactobacillus acidophtlus, Lactobacillus delbrueckii, and Lactobacillus leichmannii failed to grow in semisynthetic media similar to those used for vitamin assay with other lactic acid bacteria, even though all of the then known B vitamins were added. Since that time oleic acid (Will...

B-vitamin assays with chicks. 2 89 Roberts, E. C. & Snell, E. E. (1946). J. bid. Chem. 163, 499. Rosen, F., Huff, J. W. & Perlzweig, W. A. (1946). J. bid. Chem. 163, 343. Snell, E. E. & Rannefeld, A. N. (1945). J. bid. Chem. 157, 475. Sreenivasan, A., Harper, A. E. & Elvehjem, C. A. (1949). J. bid. Chem. 177, 117. Stokstad, E. L. R., Jukes, T. H., Pierce, J. . Page, A. C. & Franklin, A. L. (194...

We analyze the robustness properties of the Snell envelope backward evolution equation for the discrete time optimal stopping problem. We consider a series of approximation schemes, including cut-off type approximations, Euler discretization schemes, interpolation models, quantization tree models, and the Stochastic Mesh method of Broadie-Glasserman. In each situation, we provide non asymptotic...