新基建发展对产业升级的影响机制研究

新基建作为现代化基础设施体系的重要组成部分，已经成为中国经济高质量发展的重要支撑。基于2015—2021年中国71个城市的面板数据，构建双向固定效应、中介效应和调节效应三种回归模型，实证检验新基建发展对城市产业结构水平的影响及内在机制。研究发现：新基建发展能促进产业高级化水平，改善不合理的产业结构状态，提升产业合理化水平；新基建通过发展物联网和激励城市研发创新两种间接路径对产业结构转型升级产生积极影响；新基建对产业结构水平的影响受到地方政府干预行为的调节作用，在地方政府合理的行政管理下，新基建对产业转型升级的积极作用更为明显；新基建发展对产业结构水平的提升作用具有区域异质性和城市规模异质性，在中西部地区和大城市地区的作用效果更为明显。     

Trade liberalization and wage inequality: Evidence from Korea

This paper investigates the heterogeneous income distribution effects of trade liberalization using Korean survey data from years of 2000–2015. Following the Stolper-Samuelson theorem most of previous research studying the effects of trade liberalization on wage differences focus on workers’ characteristics (e.g., skilled or unskilled) while heterogeneity within the same worker group has not been yet substantially investigated. To fill this gap, this paper provides empirical evidence of wage inequality across firms within the same group of workers caused by trade liberalization, potentially implied in the new-new trade models with firm heterogeneity. Employing a difference-in-differences (DID) specification, we find that the wages of unskilled workers in Korea have increased since its FTAs with more advanced countries, such as members of EU and the US, came into effect, while the effects on the wages of skilled workers are negative but not statistically significant. We also show that wage effects are heterogeneous across firms within unskilled and skilled worker groups, while the positive effects are statistically significant and largest for unskilled workers in medium-large sized firms. These findings are in line with both traditional and new-new trade models.     

Labor productivity forecasts based on a Beveridge–Nelson filter: Is there statistical evidence for a slowdown?

In this paper, I assess the evidence for a structural break in labor productivity growth in the years before the Great Recession with the use of out-of-sample forecasting exercises for the years 2010 to 2019 and the recently developed Beveridge–Nelson filter. Models based on a Beveridge–Nelson filter with no structural breaks outperform those allowing for a structural break, and there is statistically significant evidence that they outperform the random walk, though all models were too optimistic about labor productivity growth. Recently developed statistical tests do point to the presence of a structural break before the Great Recession, but uncertainty about the data-generating process for labor productivity growth or the timing and magnitude of the break may be too great to be helpful in forecast preparation.     

Factor Heterogeneity,Factor Market Imperfection and Trade

This paper develops a tractable model of examining how factor heterogeneity and imperfect factor market interact for determining a pattern of trade. Institution plays a crucial role for the interaction. In my work, firm productivity is defined as a composition of factor productivity and technology. Thus, input selection should affect the pattern of Melitz’s intra-industry allocation due to the incurring transaction cost. For a simple model, I assume two factors (labor and capital) and two sectors, which are relatively less institution-dependent and relatively more institution-dependent. When the economy is open, effect of the transaction cost on income distribution is more drastic for an institutionally underdeveloped country. Depending on institutional quality, the economic openness reallocates resource across countries through job creation or job destruction. The job turnovers redistribute income between heterogeneous labors within countries. The income redistribution is catalyzed by international mobility of capital. As a result, income disparity is widened between the institutionally developed country and the institutionally underdeveloped country. This paper can contribute to the literature of institution and international trade.     

工资对个人劳动供给的非线性影响：部门市场化程度差异视角

从市场经济体制的建立到经济社会高质量发展，我国不同部门市场化程度有所差异，劳动供给的部门异质性随之体现。基于中国劳动力动态调查数据，结合汉森门槛回归模型和劳动供给模型，依托部门市场化程度的差异性，文章探讨了工资对劳动力个人供给的非线性影响及其部门异质性。主要得出以下研究结论：第一，我国市场部门与公共部门劳动力的个人劳动供给有所差异。第二，工资与个人劳动供给呈现非线性关系并且存在部门异质性。实证分析结果显示，工资对个人劳动供给的影响存在三个"突变点"，工资门槛均使得工资"激励效应"加强并呈现逐步增加的趋势。第三，劳动供给的工资门槛存在性别、城乡和行业异质性。第四，随着年龄增长、人力资本积累，个人劳动时间供给趋于降低，签署书面劳工合同使得市场部门劳动力工作时间显著增加，而政治面貌显著影响公共部门劳动供给。总体来看，无论是市场部门还是公共部门，我国劳动力个人供给曲线均未"向后弯曲"，国民经济高质量发展、改善收入分配格局、提升居民幸福感等议题需持续关注。     

Labor market analysis through transformations and robust multivariate models

The work presents a robust approach to labor share analysis. The estimate of labor share presents various complexities related to the nature of the data sets to be analyzed. Typically, labor share is evaluated by using discriminant analysis and linear or generalized linear models, that do not take into account the presence of possible outliers. Moreover, the variables to be considered are often characterized by a high dimensional structure. The proposed approach has the objective of improving the estimation of the model using robust multivariate regression techniques and data transformation.     

Determinants of Current Account Imbalances in 16 OECD Countries: An Out-Of-Sample Perspective

We employ panel data as well as country-specific models to uncover empirically the determinants of current account imbalances. We find evidence of slope heterogeneity likely rendering the fixed-effect estimator inconsistent. Mean group estimation is followed to overcome the latter difficulty. Both estimation techniques are evaluated by means of in- and out-of-sample criteria. The mean group estimator outperforms the fixed-effect approach and, moreover, only three economic variables are found to impact on the current account balance significantly. These are the government budget balance, the domestic output gap and the changes of the terms of trade. We finally propose a parsimonious dynamic model of the current account, including only these variables and illustrate that it has similar predictive accuracy as country-specific benchmark models. JEL no. F32, C23, C53     

Labor income and risky investments: can part-time farmers compete?

In the developed countries, a majority of farm households receive at least as much income from nonfarm sources as from the farm. Such part-time farms have survived inspite of lower returns than full-time farms. This paper considers when lower returns to part-time farming could be compensated by risk-reduction due to diversification of income sources. The paper uses a dynamic portfolio choice model with labor income. The model and results could be applied in other contexts as well.     

仓库物资装卸最优性方案的选择

军队后方仓库是军用物资装备的储备基地，是军队物流系统的一个重要环节。如何利用现有条件，提高日常乃至战时仓库的收发、存储能力和工作效率，是提高军队后勤保障能力的一个重要课题。本文对仓库物资装卸中的几个主要技术经济指标进行探讨分析。