Want to know where House Speaker Tom Craddick found the $15 billion he's labeled as "surplus" funds?

The Speaker told a South Texas audience the Legislature will start its next session with $15 billion unspent and in the bank.

Lawmakers knew they'd left money on the table last session. Budgeteers said they were spending less than they had available out of caution, since they didn't (and still don't) know how much money the new business margins tax would bring in.

But the numbers are boosted further by high oil prices and the taxes based on them, and from higher-than-expected sales tax revenues over the last year and more.

Look at the back of Craddick's envelope: He's starting with numbers released by Comptroller Susan Combs last year that included two significant bumps. First, she said the state had, through the end of last August, brought in $2 billion more than her earlier projections (the ones used by lawmakers writing the budget). Second, the economic good times had swollen the Rainy Day Fund to $5.7 billion, up from her estimated $4 billion. And there's the $3 billion set aside for property tax relief in the current budget. Those add up to $10.7 billion.

If you assume, as Craddick apparently does, that the numbers will continue on this trajectory, you can add $4 billion to $5 billion to that number by the end of the budget period in August 2009.

State agencies have to bring their proposed budgets to the Legislature in July and August. At that point, you'll start to get an idea of how their spending proposals match up with the revenue projects. That's when you'll see the actual difference between what's needed and what's available. If you want precision in language, that's when you'll know whether there's really a surplus in the state budget or a deficit.

For now, without seeing what it would cost the state to do what it's already doing (not to mention areas where it might want to add to spending), Craddick sees that as a $15 billion bouquet.