Simulation of Einstein-Podolsky-Rosen experiments in a local hidden variables model with limited efficiency and coherence

We simulate correlation measurements of entangled photons numerically. The model employed is strictly local. The correlation is determined by its classical expression with one decisive difference: we sum up coincidences for each pair individually. We analyze the effects of decoherence, detector efficiency and polarizer thresholds in detail. The Bell inequalities are violated in these simulations. The violation depends crucially on the threshold of the polarizer switches and can reach a value of 2.0 in the limiting case. Existing experiments can be fully accounted for by limited coherence and non-ideal detector switches. It seems thus safe to conclude that the Bell inequalities are no suitable criterium to decide on the nonlocality issue.