AUTOMATIC EFFECTS CAUSE DEFICIT SPENDING

People rant and rave that the Congress can't keep the budget balanced. They blame political interests for causing the deficit. There is another force at work here. It is an unseen force, straight from the world of probability mathematics:



ITEM-BY-ITEM SPENDING

Assume a 9-member city council, where each councilman gets an equal vote. Let there be $100,000 available to be spent, and suppose there are enough small programs vying for that money that they total $120,000. Also assume that each councilman analyzes the available budget items before the meetings, and randomly decides what items to vote for and against. Let's look at a typical budget process, and what goes wrong:

How can this be? The answer is that the probability of an item passing is NOT 5/6.

Here is an analysis of the probability of a budget item passing the council. Since each councilman chooses randomly, the probability an item passes is found using the Binomial Distribution on a simple majority vote:

SUM [C(9,x) * (5/6)^x * (1/6)^(9-x), for x = 5 to 9] = .99065.

Google the Binomial Distribution to understand this probability function.

Use the mean of a Binomial Distribution to find the number of items that pass. Multiplying the budget by the probability of passing approximates this. If each item has a .99065 probability of passing, then the budget will be overspent, because $120,000 times .99065 is $118,878, or $18,878 over budget.

Another way to see this is to look at the votes in a table: Green values are within budget. Red values are over budget:


PROJECTSVOTED
TOTALS
Proj #1234 5678
Cost:$20000$20000$20000$20000 $10000$10000$10000$10000$120000
COUNCIL
MEMBERS
1noYESYESYES YESYESYESYES$100000
2YESYESYESYES YESnoYESno$100000
3YESnoYESYES YESYESYESYES$100000
4YESYESnoYES YESYESYESYES$100000
5YESYESYESYES noYESYESno$100000
6YESYESYESno YESYESYESYES$100000
7noYESYESYES YESYESYESYES$100000
8YESYESYESYES YESYESnono$100000
9YESYESYESYES noYESYESno$100000
Yes Votes:7 of 98 of 98 of 98 of 9 7 of 98 of 98 of 95 of 98 pass
Budgeted:$20000$20000$20000$20000 $10000$10000$10000$10000$120000

Even though each councilman planned for and voted for a balanced budget, the government overspent. Hence, these conjectures follow:

ALL of these conjectures assume a simple majority vote is taken on each budget item in sequence:



OMNIBUS BUDGET BILL SPENDING

If an omnibus spending bill is prepared in advance by a committee, the same conjectures apply, but the probability of overspending is even greater in a bicameral legislature.

Assume the same conditions as above, that the two houses have 9 members each, and that each legislator again makes up his list of items to vote for in advance. Then the probability a legislator favors a particular spending item is again 5/6, and the probability that the lower house favors an item is:

SUM [C(9,x) * (5/6)^x * (1/6)^(9-x), for x = 5 to 9] = .99065.

So the probability that the lower house does NOT favor the item is .00935
(The probability of failure is 1 minus the probability of success.)

The probability that the upper house favors the item is also:

SUM [C(9,x) * (5/6)^x * (1/6)^(9-x), for x = 5 to 9] = .99065.

Again, the probability that the upper house does NOT favor the item is .00935

With an omnibus budget bill, BOTH houses must vote to AMEND the bill to remove the item, before it can be removed. This does NOT agree with the method prescribed in the Constitution. Only once outcome, instead of three, removes the bill. So the probability of removing a spending item is even lower:

.00935 * .00935 = .0000874225

The probability of the item passing is therefore:

1 - .0000874225 = .9999125775

This is even worse than any of the cases above.


The omnibus spending bill violates constitutional intent.

First, the case of the constitutional method. Assume the following:

  1. A bicameral legislature with each house larger than 40 members (so the normal distribution applies).
  2. The bill is for an individual spending item.
  3. Each legislator, and the executive, flips a coin to decide how to vote (an even chance of voting for or against).

Then the probability that the bill passes is shown by the following table:

First HouseSecond HouseExecutiveProbabilitiesResultSpending
.05 Supermajority (2/3).05 Supermajority (2/3).50 Signed.00125Pass Probability
of spending:
 
.12625
.50 Vetoed.00125Pass Override
.45 Majority.50 Signed.01125Pass
.50 Vetoed.01125Fail Vetoed
.50 DefeatedNo Action.025Fail Defeated
.45 Majority.50 MajoritySigned.1125Pass
Vetoed.1125Fail Vetoed
.50 DefeatedNo Action.225Fail Defeated
.50 DefeatedNo ActionNo Action.5Fail Defeated

With a probability of .12625 using the constitutional method, legislators have to really want to spend the money to spend it.

If the President always passes the budget, the problem simplifies to:

First HouseSecond HouseExecutiveProbabilitiesResultSpending
.50 Majority.50 majority1.0 Signed.25Pass (spent) Probability
of spending:
 
.25
.50 Defeated1.0 Signed.25Fail (not spent)
.50 DefeatedNo Action1.0 Signed.5Fail (not spent)

With a probability of .25 legislators still have to really want to spend the money to be able to spend it.


Now, the case of the omnibus budget bill method. Assume the following:

  1. A bicameral legislature with each house larger than 40 members (so the normal distribution applies).
  2. The vote is on removing an item from the omnibus budget bill.
  3. Each legislator flips a coin to decide how to vote (an even chance of voting for or against).
  4. It is assumed that the executive signs the resulting budget bill, so no veto override is needed.

Then the probability that the money is spent on the item is shown by the following table:

First HouseSecond HouseExecutiveProbabilitiesResultSpending
.50 Majority.50 majority1.0 Signed.25Pass (not spent) Probability
of spending:
 
.75
.50 Defeated1.0 Signed.25Fail (spent)
.50 DefeatedNo Action1.0 Signed.5Fail (spent)

With the .75 probability of spending with the omnibus budget method, legislators must really want to not spend the money to not spend it.

This entire section shows that no legislature can control spending by itself, without special processes to prevent spending into debt.



SOLUTIONS

Now that we know the problem exists, what can be done about it? We know that, to get a balanced budget, these things must be avoided:

  1. Avoid sequential voting on budget items.
  2. Legislators must not stick to plans made in advance, unless a system to prevent overspending is in place.
  3. Simple majority votes do not work without a system to prevent overspending.
  4. Omnibus spending bills must be avoided.

Here are some suggestions on what to do, with good and bad points of each:

Using these measures can once again get our government spending under control.

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