Thank you.
But I suspect the ITBIS is a sales tax. The VAT works in another way. It is applied at all levels of the production cycle, but recuperated by intermediary suppliers and therefore paid only by the end-purchaser. That is why it appears to be a generalized sales tax, but is not only a sales tax on the final product.
For instance, a manufacturer of goods would buy from component producers certain pieces that are incorporated in the manufacture of thier product. When they sell their product to a distributor with the VAT included, they recuperate the VAT they paid on all the component parts. The distributor pays the manufacturer the price of the product plus the VAT, adds his margin, resells the product to the end-buyer and sends the VAT revenues to the state, but then recuperates the VAT they have paid in purchasing the finished product.
The difference between what the VAT they pay and what they recuperate is the percentage of the VAT paid on the "added-value" in each step of the manufacturing/distribution process. This amounts to a sizable revenue for state coffers beyond just an end-user sales tax.
In fact, in most European countries, the VAT collects anywhere from 60 to 70% of all tax revenues. The income tax being only a minor percentage of total tax revenues. The VAT was instituted in Europe, therefore, because governments knew that people would cheat on income taxes, but companies could not avoid paying the VAT.
In fact, underestimating income for purposes of taxation still happens in Europe ... and all around the world.
NB: I suspect the DR tax authorities know very well how a VAT works, and if it has not been introduced there are reasons. It is a very difficult tax to administrate since it is applied at all levels of transactions requiring not only collection of the tax but reimbursement to service/product suppliers. It also requires an army of "inspectors" to assure that suppliers are actually paying the tax.