Predicting Non-Observable Parameters for Digital Components

Systems, methods, devices, and techniques for improving the efficiency of selecting digital components to present in electronic documents and reducing latency in rendering digital components in electronic documents. In some implementations, a content distribution system uses predicted metrics for a set of candidate components to determine items to present in an electronic document responsive to a request. A metric prediction model can generate predicted metrics with the aid of a parameter prediction sub-model that predicts a value of a non-observable parameter associated with a request for a digital component.