State tax reform in Wisconsin is being discussed to modernize the tax system. The state currently uses formulary apportionment for corporate income tax, but lacks combined reporting. Combined reporting would prevent businesses from shifting income to tax havens, potentially increasing state revenue. This change may face opposition from some businesses but could benefit the state by attracting and retaining businesses through customized tax policies. The focus is on ensuring fair taxation and measuring the impact of tax changes on businesses' profitability.