Environmental Policy in Vertical Chains with Endogenous Technology Portfolio

We analyse the impact of environmental policy in a vertical chain where an upstream monopolist uses a mixed portfolio, consisting of a polluting and a green technology. We examine and compare a no-intervention benchmark, a green subsidy, an abatement tax, a mandatory green standard, and a combined policy (mandatory standard and tax), where policy instruments maximize welfare. Compared to the benchmark, prices are higher (lower), total output is smaller (larger), green capacity is larger, polluting capacity, profits, and consumer surplus are smaller (larger), and social welfare is greater in a tax regime where the instrument binds (in a subsidy regime). For low enough damage levels, optimal tax is zero so a tax regime is outcome-equivalent to the benchmark, otherwise the optimal tax binds. A subsidy leads to larger green capacity than a tax and, unless the damage is high enough, to lower polluting capacity and greater welfare. A mandatory standard is outcome equivalent to a subsidy, except for the upstream manufacturer, who strictly prefers the latter. For small enough damage, a combined policy benefits not only society but also the consumers and the retailers relative to the benchmark