While conventional agreements on international public goods require bilateral or multilateral cooperation, we show that unilateral action through matching mechanisms with a self‐commitment device can possibly generate Pareto‐improving outcomes. Even without commitment, unilateral matching may also benefit both players at corner situations. We further characterize the conditions under which this desirable outcome is achieved, particularly highlighting the role of the income distribution and its interplay with the preferences. Moreover, we propose a variant of unilateral matching that can generate Pareto‐improving outcomes regardless of the preferences and the income distribution, indicating that income inequality may not be an obstacle for improving public good provision through unilateral matching.

This paper examines carbon tax design options in the United States using an intertemporal computable general equilibrium model of the world economy called G-Cubed. In this paper, we discuss four policy scenarios that explore two overarching issues: (1) the effects of a carbon tax under alternative assumptions about the use of the resulting revenue, and (2) the effects of a system of import charges on carbon-intensive goods (“border carbon adjustments” or BCAs). Consistent with earlier studies, we find that the carbon tax raises considerable revenue and reduces CO2 emissions significantly relative to baseline, no matter how the revenue is used. Gross annual revenue from the carbon tax with lump sum rebating and no BCA begins at $110 billion in 2020 and rises gradually to $170 billion in 2040. By 2040, annual CO2 emissions fall from 5.5 billion metric tons (BMT) under the baseline to 2.4 BMT, a decline of 3.1 BMT, or 57%. Cumulative emissions over 2020 to 2040 fall by 48 BMT. Also consistent with earlier studies, we find that the carbon tax has very small overall impacts on gross domestic product (GDP), wages, employment, and consumption. Different uses of the revenue from the carbon tax result in slightly different levels and compositions of GDP across consumption, investment and net exports. Overall, using carbon tax revenue to reduce the capital income tax rate results in better macroeconomic outcomes than using the revenue for lump sum transfers. Counter to their purported purpose of protecting U.S. trade strength, for a given revenue policy, BCAs tend to produce lower net exports than the carbon taxes alone. This is generally because the BCAs raise the value of the dollar relative to other currencies, thus lowering exports more than they lower imports. This is consistent with standard results in the international trade literature on the effects of import tariffs and export subsidies on real exchange rates, a result that is often overlooked in the discussion of domestic carbon policy. In a finding new to the literature, our results show that BCAs can have strikingly different effects depending on the use of the revenue. Under a lump sum rebate, BCAs exacerbate the impact of the carbon tax by lowering domestic output further than it would fall under the carbon tax alone. Under a capital tax swap, however, BCAs have a moderating effect: they reduce the impact of the tax on most industries.

Matching mechanisms have been proposed to improve public good provision in voluntary contributions. However, such decentralized subsidizing mechanisms may not be Pareto‐improving and may suffer from incomplete information and incredible commitment. This paper examines participation constraints of matching mechanisms with small matching rates in two cases of equilibria. At interior equilibria, there always exist small Pareto‐improving matching schemes regardless of preferences. This universal existence is useful for cooperation among heterogeneous players in the context without global information of preferences or at the international level without central governments. At corner equilibria, matching schemes work in different ways and have distinct welfare effects in certain cases, and the existence of Pareto‐improving matching schemes is not universal but is possible under certain conditions. The paper further characterizes Pareto‐improving matching schemes, and shows that it is easier to reach Pareto‐improving matching outcomes if players value more on public goods and have stronger substitution between private and public goods.

This paper explores the economic impacts of Korean unification on North and South Korea. It presents a new consistent database on macroeconomic, sectoral and trade data, and an input-output table for the North Korean economy, and then incorporates it in a global intertemporal multi-sector general equilibrium model. Assuming hypothetical scenarios such as North Korea's reform and gradual convergence, its sudden collapse and immediate unification, and chaos and crises in both Koreas, we quantify the consequences of Korean unification on economic activity, trade and capital flows in the two Koreas. The results highlight the importance of the unification processes and of alternative policy responses in both Koreas to the economic impacts of unification.

The world has been experiencing dramatic demographic change since the 1950s, with almost all countries facing ageing challenges this coming century. However, the timing and speed of this demographic transition are significantly asymmetric across countries. This paper examines the impacts of global demographic change on macroeconomic conditions, international trade and capital flows in major economies in a global multi-region and multi-sector general equilibrium model. We separately simulate demographic shocks in six regions of the world economy to understand how each shock individually affects the world economy and then combine these shocks to obtain the consequences of global demographic change. The paper finds that future demographic change will significantly impact each region's GDP, changing the landscape of the world economy.However, the spillover effects on GDP across the countries are relatively small. In young economies such as emerging Asia and Africa, while economic growth will significantly benefit from demographic dividends, demographic change does not improve per capita GDP. In ageing economies such as Japan and Europe, population ageing will decrease the real interest rate. However, this impact will be offset by rising interest rates in young economies. Due to the differential real interest rates, capital will flow from more ageing to less ageing economies. These capital flows can be substantial and beneficial for all economies.