I was wrong: SAS does have decent random number generation

Here and other places I've been dissing on SAS's random number generation capabilities as unsuitable. Well, it turns out that I'm at least half wrong. If you use the ranuni or other ran___ series of random number generators, you still have the 2³²-1 period generator. SAS's implementation is top of the line of this class of generators, but the class is unsuitable for anything but the simplest of tasks (or teaching demonstrations). Serious modern clinical trial simulation tasks require a period of at least 2⁶⁴.

Enter SAS's RAND function. RAND takes a string argument that identifies the distribution (e.g. uniform or normal) followed by enough numerical parameters to identify the class member (e.g. normal requires either 0 or 2 numerical parameters&emdash;0 parameter gives you an N(0,1) distribution and 2 parameters identify the mean and variance). The special thing about RAND is that it is based on the Mersenne twister algorithm, which has a period of 2¹⁹⁹³⁷-1 and very good "randomness" properties.

So I hereby recant my criticism of SAS's PRNG capabilities.