Welfare effects of the Telecommunication Reform in Mexico

The telecommunication sector in Mexico was highly concentrated until 2013. The sector was mostly composed by a dominant player, a rationed market (low density of services), a poor institutional design, high tariffs, and weak regulation agents. The Herfindahl-Hirschman (HHI) index was 5333 for mobile telephone and 7,029 for fixed telephone services—among the highest scores in the world. In order to promote competition in the sector, Congress approved a reform in 2013 to establish a new regulator empowered to impose asymmetrical rules in the case of the predominance of a single firm. A declaration of preponderance of the dominant player was issued, promoting free interconnection rates and the mandatory sharing of its passive and active infrastructure with the rest of the firms in the industry. The new institutional design led to increased competition in the sector, decreasing the mobile and fixed telephone prices while increasing the coverage and penetration of these services. In this article, an applied general equilibrium model for the Mexican economy is employed to assess the impact of the Telecommunication Reform in Mexico in the telephone sector, consumer welfare, and income distribution. The model is static, encompassing 10 types of consumers (rural and urban and the five income quintiles) and 40 sectors (of which four are disaggregate telecommunications industries). It assumes fixed wages and capital rental prices as well as idle resources. The main results indicate that the effects of the reform are not minor; the drop in telephone prices would reduce the general consumer price index by almost 2%, and the value added would increase by more than 3%, benefiting mainly households in the highest income quantiles.     

Robustness to strategic uncertainty

We introduce a criterion for robustness to strategic uncertainty in games with continuum strategy sets. We model a player's uncertainty about another player's strategy as an atomless probability distribution over that player's strategy set. We call a strategy profile robust to strategic uncertainty if it is the limit, as uncertainty vanishes, of some sequence of strategy profiles in which every player's strategy is optimal under his or her uncertainty about the others. When payoff functions are continuous we show that our criterion is a refinement of Nash equilibrium and we also give sufficient conditions for existence of a robust strategy profile. In addition, we apply the criterion to Bertrand games with convex costs, a class of games with discontinuous payoff functions and a continuum of Nash equilibria. We show that it then selects a unique Nash equilibrium, in agreement with some recent experimental findings.     

Addressing climate change cause and effect on land cover and land use in South Asia

This paper evaluates the role of trade liberalization and agricultural intensification in mitigating climate change cause and effects on land use and emissions using a computable general equilibrium model. Our results indicate that cropland expansion triggered by climate-induced crop productivity changes results in deforestation and increases emissions in South Asia and globally. Global full trade liberalization on all goods is the optimum policy for South Asia despite significant global deforestation, but for the world, unilateral partial trade liberalization on all goods is a more appropriate policy while ensuring a considerable emissions reduction for South Asia. These results indicate that mitigation responses to climate change are location specific and no one trade policy is suitable at the regional and global levels. Lastly, agricultural intensification by improving productivity growth is the best strategy in land-based emissions mitigation, thereby avoiding the transformation of forest and pasture lands for agricultural cultivation both at regional and global levels.     

The veto mechanism in atomic differential information economies

We establish new characterizations of Walrasian expectations equilibria based on the veto mechanism in the framework of differential information economies with a complete finite measure space of agents. We show that it is enough to consider the veto power of a single coalition, consisting of the entire set of agents, to obtain the Aubin private core. Moreover, we investigate on the veto power of arbitrarily small and big coalitions, providing an extension to mixed markets of well known Schmeidler (1972) and Vind’s (1972) results in terms of Aubin private core allocations.     

Life Expectancy Heterogeneity and the Political Support for Collective Annuities

Individuals, differing in productivity and life expectancy, vote over the size and type of a collective annuity. Its type is represented by the fraction of the contributive (Bismarckian) component (based on the worker's past earnings) as opposed to the non‐contributive (Beveridgean) part (based on average contribution). The equilibrium collective annuity is either a large mostly Bismarckian program, a smaller pure Beveridgean one (in accordance with empirical evidence), or nil. A larger correlation between longevity and productivity, or a larger average life expectancy, both make the equilibrium collective annuity program more Beveridgean, although at the expense of its size.     

网购市场鱼龙混杂现象的经济学解释：基于二维不对称信息的视角

网络购物市场存在商品鱼龙混杂的典型现象：高价格的商品不一定高质量，低价格的商品也不一定低质量，表现出明显的信息不对称特征。文章基于网络购物市场所存在的两个维度不对称信息的特征事实，即厂商在产品质量与产品生产成本两个方面拥有私有信息，通过构建二维不对称信息的分析框架，从市场均衡的视角首次解释了上述现象的经济机理。分析表明，由于二维不对称信息的存在，消费者和厂商决策的互动过程使得市场上产品价格与质量不再具有单调递增关系，从而网络购物市场可能出现鱼龙混杂的市场均衡，文章证明了这一均衡在合理的条件下是存在的。文章通过比较静态分析考察了市场环境的变化如何影响商品质量的价格信号显示效率以及消费者购买行为，并考察了网络购物行业商家披露信息、消费者对于商家的反馈评分机制和保证退货等手段对于消除商品鱼龙混杂现象的有效性，为进一步规范发展我国网络购物行业提供了参考。     

REDISTRIBUTIVE POLITICS AND GOVERNMENT DEBT IN A BORROWING‐CONSTRAINED ECONOMY

We develop a two‐period, three‐class of income model where low‐income agents are borrowing constrained because of capital market imperfections, and where redistributive expenditure is financed by tax and government debt. When the degree of capital market imperfection is high, there is an ends‐against‐the‐middle equilibrium where the constrained low‐income and the unconstrained high‐income agents favour low levels of government debt and redistributive expenditure; these agents form a coalition against the middle. In this equilibrium, the levels of government debt and expenditure might be below the efficient levels, and the spread of income distribution results in a lower debt‐to‐GDP ratio.     

A comparison of programming languages in macroeconomics

We solve the stochastic neoclassical growth model, the workhorse of modern macroeconomics, using C++14, Fortran 2008, Java, Julia, Python, Matlab, Mathematica, and R. We implement the same algorithm, value function iteration, in each of the languages. We report the execution times of the codes in a Mac and in a Windows computer and briefly comment on the strengths and weaknesses of each language.     

Bond Pricing with a Time‐Varying Price of Risk in an Estimated Medium‐Scale Bayesian DSGE Model

New Keynesian model in which households have Epstein–Zin preferences with time‐varying risk aversion and the central bank has a time‐varying inflation target can match the dynamics of nominal bond prices in the U.S. economy well. The model generates a large steady‐state term spread and its fitting errors for bond yields are comparable to those obtained from a nonstructural three‐factor model, and one‐third smaller than in models with a constant inflation target or risk aversion. Including data on interest rates has large effects on variance decompositions, making investment technology shocks much less important than found in other recent papers.