A recent study found that in "countries with per capita incomes of below USD 15,000 per year (at PPP-adjusted 2011 USD) carbon pricing has, on average, progressive distributional effects" and that "carbon pricing tends to be regressive in countries with relatively higher income," indicating that carbon taxing and shifting carbon prices might incentivize governments to shift to green energy as the baseline energy consumption method for developing peri-urban areas.[39] Although urbanization is seen in a positive light, the effects of it can be negative on those being urbanized.