THE DEMAND FOR LIQUID ASSETS,CORPORATE SAVING,AND INTERNATIONAL CAPITAL FLOWS

The recent period of capital outflows from emerging economies has coincided with an increase in their corporate saving. In this paper, we model corporate saving as a demand for liquid assets by credit‐constrained firms in a dynamic open‐economy macroeconomic model. We find that the implications of this model are very different from standard models, because the demand for foreign bonds is a complement to domestic investment rather than a substitute. We show that this complementarity is at work when an emerging economy is on its convergence path or when it has a higher TFP growth rate. This framework is consistent with a number of stylized facts found in high‐growth, high‐investment emerging economies.     

What's News in Business Cycles

In the context of a dynamic, stochastic, general equilibrium model, we perform classical maximum likelihood and Bayesian estimations of the contribution of anticipated shocks to business cycles in the postwar United States. Our identification approach relies on the fact that forward‐looking agents react to anticipated changes in exogenous fundamentals before such changes materialize. It further allows us to distinguish changes in fundamentals by their anticipation horizon. We find that anticipated shocks account for about half of predicted aggregate fluctuations in output, consumption, investment, and employment.     

Inefficient Job Destructions and Training with Hold‐up

This paper develops an equilibrium search model with endogenous job destructions and where firms decide at the time of job entry how much to invest in match‐specific human capital. We first show that job destruction and training investment decisions are strongly complementary. It is possible that there are no firings at equilibrium. Further, training investments are confronted to a hold‐up problem making the decentralized equilibrium always inefficient. We show therefore that both training subsidies and firing taxes must be implemented to bring back efficiency.     

人口老龄化、金融资产结构与宏观经济波动效应

本文构建了一个包含平均年龄异质性家庭和创新异质性企业的动态随机一般均衡模型,模拟分析人口老龄化对宏观经济的冲击效应得出:随着中国人口老龄化程度的提高,家庭持有的流动性金融资产占金融总资产的比例上升、资本性金融资产所占比重逐渐下降,从而引起宏观金融结构的变动;中国人口老龄化引发的金融结构变动将导致劳动减少、消费减少、产出降低,甚至影响企业创新投资降低,进而导致高投资的经济增长模式发生变化。研究结论的政策含义在于:劳动增长依赖、投资增长依赖、技术模仿依赖都难以为继,经济高质量发展的动力应集中到创新方面,激励企业技术创新是市场机制改革的重要方向,引导市场资金对技术创新型企业的投资支持,同时应避免企业技术创新投资的剧烈上涨造成经济震荡。     

MANAGING CREDIT BUBBLES

We study a dynamic economy where credit is limited by insufficient collateral and, as a result, investment and output are too low. In this environment, changes in investor sentiment or market expectations can give rise to credit bubbles, that is, expansions in credit that are backed not by expectations of future profits (i.e., fundamental collateral), but instead by expectations of future credit (i.e., bubbly collateral). Credit bubbles raise the availability of credit for entrepreneurs: this is the crowding‐in effect. However, entrepreneurs must also use some of this credit to cancel past credit: this is the crowding‐out effect. There is an “optimal” bubble size that trades off these two effects and maximizes long‐run output and consumption. The equilibrium bubble size depends on investor sentiment, however, and it typically does not coincide with the “optimal” bubble size. This provides a new rationale for macroprudential policy. A credit management agency (CMA) can replicate the “optimal” bubble by taxing credit when the equilibrium bubble is too high and subsidizing credit when the equilibrium bubble is too low. This leaning‐against‐the‐wind policy maximizes output and consumption. Moreover, the same conditions that make this policy desirable guarantee that a CMA has the resources to implement it.     

考虑技术投资的供应链网络下可交易污染排放许可均衡问题

构建了包含多污染物、多污染接收点的供应链网络,考虑了生产技术和减排技术投资,对可交易的污染排放许可下的供应链网络进行了均衡分析,给出了变分不等式框架,建立了均衡模型。模型明确地处理了空间差异,同时保证了通过初始污染排放许可分配就可达到指定的环境标准。提出了模型的求解算法,最后利用提出的模型及算法对算例进行了计算,得到利润最大化下供应链网络中各工厂的产品生产量、排放量、污染排放许可的均衡分配额和污染排放许可的交易价格、技术最优投资额,并分析了成本函数参数以及工厂数量的变化对生产技术投资和减排技术投资的影响。     

Explaining Investment Dynamics in U.S. Manufacturing: A Generalized (S,s) Approach

In this paper we derive a model of aggregate investment that builds from the lumpy microeconomic behavior of firms facing stochastic fixed adjustment costs. Instead of the standard sharp (S,s) bands, firms' adjustment policies take the form of a probability of adjustment (adjustment hazard) that responds smoothly to changes in firms' capacity gap. The model has appealing aggregation properties, and yields nonlinear aggregate time series processes. The passivity of normal times is, occasionally, more than offset by the brisk response to large accumulated shocks. Using within and out-of-sample criteria, we find that the model performs substantially better than the standard linear models of investment for postwar sectoral U.S. manufacturing equipment and structures investment data.     

考虑溢出效应的互补品企业间广告决策模型研究

具有需求信息优势的企业常常将广告投入作为市场需求信号,有选择地向其互补品生产企业传递需求信息,以刺激其增加广告投入,通过溢出效应获取更大收益。针对这一问题,本文建立了考虑溢出效应的互补品企业间广告决策的信号博弈模型,得到了分离均衡和混同均衡的存在条件,分析了均衡状态下企业的最优广告决策和收益,讨论了企业的广告策略选择。结果表明,分离均衡下,具有信息优势的制造商无法利用广告投入信号刺激其互补品制造商增加广告投入。混同均衡下,只有当市场需求为低时,具有信息优势的制造商能够利用广告投入信号,刺激其互补品制造商增加广告投入,通过溢出效应获得更大收益。最后,通过一个数值算例验证了有关结论的有效性。     

PUBLIC EDUCATION AND PENSIONS IN DEMOCRACY: A POLITICAL ECONOMY THEORY

A dynamic political economy theory of fiscal policy is presented to explain the simultaneous existence of public education and pensions in modern democracies. The driving force of the model is the intergenerational conflict over the allocation of the public budget. Successive generations of voters choose fiscal policies through repeated elections. The political power of elderly voters creates the motive for adults to support public investment in the human capital of future generations since it expands future pension possibilities. We characterize the Markov perfect equilibrium of the voting game in a small open economy. The equilibrium reproduces salient features of intergenerational fiscal policies in modern economies.     

碳排放交易对实现我国“十二五”减排目标的成本节约效应研究

本文针对实现我国"十二五"期间减排目标的现实背景,构建了一个省际排放权交易模型,重点探讨了在实现各省减排目标的过程中,碳排放权交易机制发挥的成本节约效应。研究设置了无碳交易市场(NETS)、仅包含北京等六个碳交易试点省市的碳交易市场(PETS)和全国范围内实施碳排放权交易(CETS)三种政策情景。通过模型分析得到以下结论:(1)为实现"十二五"碳强度减排目标,扣除自然下降率,全国二氧化碳排放需要减少约6.39亿吨,占当年总碳排放的6.65%;无碳排放交易时全国需要付出约157.62亿元的减排成本,占当年GDP的0.04%;六省市参与碳交易情景下,全国总的减排成本约为150.66亿元,节约减排成本4.42%,碳交易量为0.22亿吨CO₂,占总减排量的3.39%,均衡碳价约为70.55元/吨CO₂;全国碳市场情景下,全国总的减排成本约为120.68亿元,相比于无碳排放交易情景节约减排成本23.44%,碳交易量为1.21亿吨CO₂,占总减排量的18.98%,均衡碳价约为38.17元/吨CO₂;(2)碳交易市场对参与交易的省份的成本节约效应各不相同,总的来看,东、西部地区成本节约较为明显,部分西部地区能够在完成自身减排目标前提下,通过加入碳交易市场而获取正的收益。     

中国汽车产业环境技术创新影响因素实证研究

基于动态计量模型,以我国汽车产业为对象,从产品创新和过程创新2个方面实证研究了环境政策、技术进步、市场结构、产业特征对汽车产业环境技术创新的影响。结果表明,环境政策中的环境影响评估制度和污染限期治理制度、技术进步中的R&D投入和人力资本存量、市场结构中的产品销售利润率与环境技术创新存在长期均衡关系,且长期均衡对产品创新短期波动的影响不大,仅有污染限期治理和R&D投入的长期均衡对过程创新短期波动的影响显著。此外,环境影响评估制度、R&D投入、人力资本存量、产品销售利润率均为产品创新和过程创新的格兰杰原因,而污染限期治理是产品创新的格兰杰原因,过程创新是污染限期治理的格兰杰原因。     

基于Heston模型时间一致的资产负债管理鲁棒策略

本文在非完备市场框架下，研究了时间一致的鲁棒最优投资组合选择问题。首先，假设金融市场由无风险资产和风险资产构成，其中风险资产的价格过程服从Heston随机波动率模型，且投资者面临一个不可控的外生负债。其次，应用随机最优控制理论，给出并证明了验证定理，建立了相应的拓展Hamilton-Jacobi-Bellman(HJB)方程组，通过求解拓展的HJB方程组，得到了鲁棒均衡投资策略和值函数的显式解。最后，通过数值模拟，给出了模型参数变动对均衡投资策略和效用改善的影响。结果表明：(1) 当风险资产的价格和其波动的相关系数大于零时，股票方差的波动越大，越不利于投资。否则反之。(2) 当风险资产的价格和其波动的相关系数越大时，风险资产的风险就越大，投资者会采取保守的投资策略，减少投资。(3) 负债的波动率变大，投资者会面临更大的负债风险，为了对冲风险，投资者会增加风险资产的投资。(4) 当投资者考虑模型不确定的影响时，采用鲁棒投资策略能显著提高投资者的效用水平。     

企业产品升级投资决策研究

本文应用期权博弈理论研究了在双寡头垄断的市场结构下,企业进行产品升级投资决策的问题,分析了在抢占均衡和同时投资均衡的情况下企业最优产品升级投资时机。研究表明,随着升级投资所导致的成本下降程度的增加,企业升级投资的临界值降低,这一结果与管理实践的直觉相一致,为企业的产品升级投资决策提供了理论指导。     

考虑双均衡的港航供应链可持续投资研究

针对港航联合可持续投资问题,构建了静态Stackelberg均衡与动态演化博弈双均衡联动模型,在政府碳排放规制和碳交易市场双重因素下,研究考虑可持续发展的港航供应链减排技术投资策略。研究表明：随着投资成本分担比例的增大,在静态Stackelberg均衡下,航运公司投资意愿逐渐降低,而港口却始终偏好自身投资,此时系统均衡策略由航运企业投资的囚徒困境转变为港口投资的帕累托最优;在动态演化博弈下,稳定结果是航运企业投资转变为港口投资。并从政府-市场-企业三方视角发现：(1)企业长期低碳投资策略与政府碳排放限额无关;(2)企业需要关注碳交易市场价格、托运人对可持续水平敏感度以及价格敏感度,这些参数值增高会降低碳排放量;(3)随着航运企业分担比例的增大,碳排放量呈现上升趋势。最后结合静态与动态投资策略,为政府、港口和航运企业可持续投资提供建议。     

LIQUIDITY AND INEFFICIENT INVESTMENT

We study consumer liquidity in a general equilibrium model where the friction is the nonpledgeability of future income. Liquidity helps to overcome the absence of a double coincidence of wants. Consumers over‐hoard liquidity and the resulting competitive equilibrium is constrained inefficient. Fiscal policy following a large negative shock can increase ex‐ante welfare. If the government cannot commit, the ex‐post optimal fiscal policy will be too small from an ex‐ante perspective. The model throws light on the holding of foreign reserves in international markets.     

The Effects of a Baby Boom on Stock Prices and Capital Accumulation in the Presence of Social Security

Is the stock market boom a result of the baby boom? This paper develops an overlapping generations model in which a baby boom is modeled as a high realization of a random birth rate, and the price of capital is determined endogenously by a convex cost of adjustment. A baby boom increases national saving and investment and thus causes an increase in the price of capital. The price of capital is mean–reverting so the initial increase in the price of capital is followed by a decrease. Social Security can potentially affect national saving and investment, though in the long run, it does not affect the price of capital.     

基于二重随机因素的对称双头垄断期权博弈模型

本文在产品市场需求与经营成本二重随机性以及二者具有相关性的条件下,建立了一个对称双头垄断期权博弈分析框架,研究了企业最优战略投资决策问题。在导出企业投资价值函数和最优投资临界值的基础上,着重分析了企业最优投资策略均衡规则及各均衡存在的条件,并就各参数对企业最优投资临界值的影响进行比较静态分析,得出了一些有意义的结论,同时给出了经济解释。     

Reputation for Quality

We propose a model of firm reputation in which a firm can invest or disinvest in product quality and the firm's reputation is defined as the market's belief about this quality. We analyze the relationship between a firm's reputation and its investment incentives, and derive implications for reputational dynamics. Reputational incentives depend on the specification of market learning. When consumers learn about quality through perfect good news signals, incentives decrease in reputation and there is a unique work–shirk equilibrium with ergodic dynamics. When learning is through perfect bad news signals, incentives increase in reputation and there is a continuum of shirk–work equilibria with path‐dependent dynamics. For a class of imperfect Poisson learning processes and low investment costs, we show that there exists a work–shirk equilibrium with ergodic dynamics. For a subclass of these learning processes, any equilibrium must feature working at all low and intermediate levels of reputation and shirking at the top.     

CONDITIONAL INVESTMENT–CASH FLOW SENSITIVITIES AND FINANCING CONSTRAINTS

We study the sensitivity of investment to cash flow conditional on measures of q in an adjustment costs framework with costly external finance. We present a benchmark model in which this conditional investment–cash flow sensitivity increases monotonically with the cost premium for external finance, for firms in a financially constrained regime. Using simulated data, we show that this pattern is found in linear regressions that relate investment rates to measures of both cash flow and average q. We also derive a structural equation for investment from the first‐order conditions of our model, and show that this can be estimated directly.     

COUNTRY PORTFOLIOS IN OPEN ECONOMY MACRO‐MODELS

This paper develops a simple approximation method for computing equilibrium portfolios in dynamic general equilibrium open economy macro‐models. The method is widely applicable, simple to implement, and gives analytical solutions for equilibrium portfolio positions in any combination or types of asset. It can be used in models with any number of assets, whether markets are complete or incomplete, and can be applied to stochastic dynamic general equilibrium models of any dimension, so long as the model is amenable to a solution using standard approximation methods. We first illustrate the approach using a simple two‐asset endowment economy model, and then show how the results extend to the case of any number of assets and general economic structure.