The Post Office is an easy target for a gifted satirist like Pratchett; macroeconomics are much harder. Pratchett manages to bring it all off, but overall "Making Money" ranks in the middle third of Pratchett's writing.
Moist Von Lipwig, confidence man, trickster and Ankh Morpork's Postmaster, is bored. And when he is bored, he will take terrible chances. In many ways, it's how he feels alive. The tyrant of Ankh Morpork, the Patrician, Lord Vetinari,recognizes all this and manipulates people and circumstances so the Moist is made the head of the city's largest bank, with a goal of monetary reform. Well, not the actual chairman; the actual head of the bank is a small dog with a taste for toffee.
Moist must cope with the old family shareholders - the completely dysfunctional Lavish clan - as well as entrenched staff, his checkered past coming back to haunt him and missing gold bullion. Moist copes better than Pratchett does. As a novel, "Making Money" is more episodic than was "Going Postal," and the conclusion is weaker. "Money" has its moments, and you will laugh out loud more than once. But as a story, it's just not as strong as, say, Pratchett's last half dozen. In particular, Pratchett doesn't pull all of the plot threads together with his usual skill.
And it must be unbelievably difficult to make economics amusing. Moist's instructions from Lord Vetinari are to get the suspicious citizens of Ankh Morpork to accept paper currency, to free the City from the gold standard. On one level, it is nearly impossible to make it funny; on another, it is nearly impossible to satirize because its satirizes itself too effectively. Pratchett gets a nod just for making the attempt. The "dismal science," to use Carlyle's phrase, could use some humor.
But even a below-average Pratchett novel is a treat, and "Money" is a delight. It's just not outstanding.