# The HPPANEL Procedure

The HPPANEL procedure is a high-performance version of the PANEL procedure in SAS/ETS^{®} software. Like the PANEL procedure, the HPPANEL procedure fits a class of linear econometric models
that commonly arise when time series and cross-sectional data are combined. This type of data on time series cross-sectional bases is often called panel data. Typical examples of panel data include
observations over time about households, countries, firms, trade, and so on. For example, in the case of survey data about household income, the panel is created by repeatedly surveying the same
households in different time periods (years).

Unlike the PANEL procedure, which can be run only on an individual workstation, the HPPANEL procedure takes advantage of a computing environment that enables it to distribute the optimization
task among one or more nodes. In addition, each node can use one or more threads to carry out the optimization on its subset of the data. When several nodes are used, with each node using several
threads to carry out its part of the work, the result is a highly parallel computation that provides a dramatic gain in performance.

Panel data models can be grouped into several categories that depend on the structure of the error term. The HPPANEL procedure uses the following error structures and their corresponding methods to analyze data:

- one-way and two-way models
- fixed-effects and random-effects models

A one-way model depends only on the cross section to which the observation belongs. A two-way model depends on both the cross section and the time period to which the observation belongs.

Apart from the possible one-way or two-way nature of the effect, the other dimension of difference between the possible specifications is the nature of the cross-sectional or time-series effect. The
models are called fixed-effects models if the effects are nonrandom and are called random-effects models otherwise.

## Documentation

For further details, see the *SAS/ETS*^{®} User's Guide: High Performance Procedures

## Examples