But not as many Kansas taxpayers need to pay estimated taxes. A cornerstone of the state’s tax cuts was a decision to exempt from tax most kinds of “pass-through” income. In most states, if you own a small business, you most likely organize it in a form such as an S-corporation, which pays no tax at the company level and passes profits through to you; you then pay tax on the profits on your individual tax return. But in Kansas, those kinds of businesses now owe no income tax at either the corporate or individual level.

One consequence of Kansas’ tax overhaul is that some taxpayers will reorganize their income, earning less taxable wages and more nontaxable profits. For example, payroll employees can become freelance contractors, collecting “consulting fees” instead of wages. To the extent those sorts of effects drove the weak tax collections this summer, there’s no reason to expect a rebound in the spring.

One reason to believe Kansas would issue a rosy estimate is that both liberals and conservatives in the state have incentives to believe in a high estimate and just cross their fingers. For conservatives, a lower revenue estimate would be embarrassing, because it shows the Brownback tax cuts were much more costly than advertised. For liberals, a lower revenue estimate would require a bigger round of state spending cuts in the short term.

A detailed memo about the estimates, which may explain why revenues would be better in the remainder of the fiscal year, should be released late this or early next week by the Consensus Revenue Estimating Group, a group made up of Kansas budget officials and state academics. Efforts to reach state officials for comment on the issue were not successful.

There may be even bigger challenges coming. In addition to the likelihood the state will face another unpleasant revenue surprise in the spring, a pending court decision could obligate the legislature to add hundreds of millions of dollars a year to state aid to school districts. And bond rating agencies, which already downgraded the state’s debt this year, could be expected to react negatively to both of those events.

The tax cuts were the leading issue in the Kansas governor’s race this year, and in addition to re-electing Governor Brownback, voters expanded the Republican supermajority in the state’s House of Representatives. This was a clear mandate for the policy of deep tax cuts. What remains to be seen is how the legislature, once the rainy-day fund is exhausted, will deal with the spending pressures they have created.