Increasing VAT while decreasing other taxes is likely to be socially regressive in its impact.  The consumption tax affects everyone in the society.  I concede that I'm not aware of whether German VAT is applied to food or other necessities such as clothing, utilities and rents.  But assuming at least some of these are caught, those people who have low, and particularly also fixed, incomes will find a higher proportion of their income is eaten up by the increased VAT on necessities compared to the proportion of high income earners' incomes.  

A few questions: will pensions be adjusted to compensate for the VAT increase under the CDU plan?  What about self-funded retirees - ie those living from interest/dividends on accumulated capital?  The value of their savings and purchasing power is instantly devalued.  Will the increased VAT fund cuts in business taxes or income tax? - more regressive still!