The example above suggests that the economic incidence problem is fundamentally one of determining how taxes change prices. In the conventional supply and demand model of price determination, the economic incidence of a tax depends on how responsive supply and demand are to prices. In general, the more responsive supply is to price, relative to demand, the greater the share of the tax that will be shifted to consumers. Intuitively, the more responsive demand is to price, the easier it is for consumers to turn to other products when the price goes up, and therefore more of the tax must be borne by suppliers. Conversely, if consumers purchase the same amount regardless of price, the whole burden can be shifted to them. In cases where the responses of supply and demand to price are well understood, then fairly reliable estimates of the economic incidence of a tax can be obtained. In some areas, the behavioral responses are not well understood, and then incidence analysis is on less firm ground. For example, there is still great controversy over the burden of taxes on corporations—to what extent are they borne by owners of capital, and to what extent by laborers? This is an important topic for research.