What do statutes not included in the Constitution limit?

The correct answer highlights that statutes not included in the Constitution limit the amount of debt the federal government can incur. This is significant because debt levels are governed by laws that can be enacted by Congress, reflecting the legislative authority to set parameters around federal borrowing. There are specific statutes that can set a debt ceiling or establish the conditions under which the government may incur obligations and borrow funds.

Statutes of this nature reflect the legal framework within which the federal government operates financially. While the Constitution does not explicitly dictate the exact amount of debt that can be incurred, it does grant Congress the power to "borrow money on the credit of the United States." This indicates that any limits on borrowing must come from statutory law rather than constitutional mandates.

In contrast, the lengths of congressional sessions, salaries of federal employees, and state budget balances are subject to other regulations and guidelines that may stem from constitutional provisions or administrative policies rather than being directly limited by statutes that define federal debt levels. Each of these areas has its own set of rules that may shift based on numerous factors, such as state laws or administrative decisions, but they don’t directly pertain to limits imposed by statutes like the federal debt does.