天津市武清区大气O_3、NO_2和CO浓度变化特征研究

文章利用2014年天津市武清区大气污染物臭氧(O_3)、二氧化氮(NO_2)和一氧化碳(CO)的监测数据,分析研究武清区O_3及其前体物NO_2和CO等大气污染物浓度水平和变化特征。结果表明武清区O_3浓度水平呈现明显的季节变化特征。夏季O_3浓度为106μg·m~(-3),冬季浓度为28μg·m~(-3),主要与光化学反应在夏季比较强烈,冬季紫外强度和平均温度均较低,光化学反应较弱有关。2014年武清区大气中NO_2年均值为51μg·m~(-3),CO年均值为1.9 mg·m~(-3),冬季是NO_2和CO浓度最高的季节。     

Lumpy Investment and Corporate Tax Policy

In the presence of both convex and nonconvex capital adjustment costs in a dynamic general equilibrium model, corporate tax policy generates both intensive and extensive margin effects via the channel of marginal Q. Its impact is determined largely by the strength of the extensive margin effect, which, in turn, depends on the cross‐sectional distribution of firms. Depending on the initial distribution of firms, the economy displays asymmetric responses to tax changes. Moreover, an anticipated increase in the future investment tax credit reduces investment and adjustment rate initially.     

Foreign investment,corporate governance and performance in the Chinese listed A Share companies

We present a novel lens on the presence and impact of qualified foreign institutional investors (QFII) in top shareholdings of the non-financial domestically listed Chinese ‘A’ share firms. The initial results suggest that the presence of a QFII as a top shareholder in these companies is associated with their better performance, using both Tobin’s Q and ROA as the performance measures. Our models include variables representing corporate governance mechanisms, foreign legal person shares, a proxy for international affiliations and a number of time-variant firm characteristics. Economically, the coefficient of impact on the market measure is the more significant, while the effect of having a QFII in top shareholdings on both performance measures is empirically significant. Previously, studies have often ignored the potential for reverse causality beyond using lagged regressors. This is problematic. Therefore, we follow up with a 2SLS instrumental variables and system GMM model to further mitigate this potential and find the empirical relationship holds. Contrary to earlier work on QFIIs and governance post-implementation of the QFII scheme, the findings from our models suggest that the presence of a QFII top shareholder augments market performance holding equal existing corporate governance mechanisms and other controls.     

Gold and the US dollar: Hedge or haven?

Using a model of dynamic conditional correlations covering 23 years of weekly data for 16 major dollar-paired exchange rates, this paper addresses a practical investment question: Does gold act as a hedge against the US dollar, as a safe haven, or neither? Key findings are as follows. (i) During the past 23 years gold has behaved as a hedge against the US dollar. (ii) Gold has been a poor safe haven. (iii) In recent years gold has acted, increasingly, as an effective hedge against currency risk associated with the US dollar.     

China's Foreign Aid at a Transitional Stage

By estimating China's foreign aid as a proxy for China's bilateral Official Development Assistance and by analyzing its implementation structure and policy, this paper sheds some light on China's foreign aid activities, which have been at a transitional stage. Based on our estimates, the level of foreign aid in terms of net disbursement has increased sharply since 2004, reaching around US$7.1 billion in 2013. Some measures to strengthen the implementation structure to deal with this expansion have been introduced by the central government; however, this transition process needs more time. To facilitate this process, China is attempting to absorb knowhow on development assistance from multilateral institutions and Organisation for Economic Cooperation and Development's Development Assistance Committee countries that are eager to share their knowledge, with the expectation that China will eventually play a major role in international development.     

Measuring stress in money markets: A dynamic factor approach

We extract an index of interest rate spreads from various money market segments to assess the level of funding stress in real time. We find that during the 2007–2009 financial crisis, money markets switched between low and high stress regimes except for brief periods of extreme stress. Transitions to lower stress regimes are typically associated with the non-standard policy measures by the Federal Reserve.     

Firm-level determinants of tax evasion in transition economies

Business tax evasion is an important issue for governments. Yet the factors that determine business tax evasion have not been sufficiently examined in the literature in general, and in transition contexts in particular. To address this gap, this study uses the WB/EBRD Business Environment and Enterprise Performance Survey (BEEPS) database with a sample of over 12,692 firms from 26 transition economies. Applying various modelling strategies, we argue that tax evasion is a function of firm-level and institutional-level variables. We contribute to the literature by providing robust evidence showing that the perceived tax burden has a positive impact on tax evasion. We also find that the tax evasive behaviour of firms is positively influenced by low trust in government and in the judicial system as well as by higher perceptions of corruption and higher compliance costs. We find that smaller firms, individual businesses and firms in sectors that are less visible to the tax administration are more likely to get involved in evasive behaviour. Overall, institutional factors play an important role in determining firms’ tax evasion behaviour in transition economies. This finding has important policy implications.     

Neighbors and the evolution of the comparative advantage of nations: Evidence of international knowledge diffusion?

The literature on knowledge diffusion shows that knowledge decays strongly with distance. In this paper we document that the probability that a product is added to a country's export basket is, on average, 65% larger if a neighboring country is a successful exporter of that same product. For existing products, growth of exports in a country is 1.5% higher per annum if it has a neighbor with comparative advantage in these products. While these results could be driven by a common third factor that escapes our controls, they align with our expectations of the localized character of knowledge diffusion.     

Unbundling democracy: Political rights and civil liberties

Much recent political economy and political science literature views democracy in terms of political rights. This view, often referred to as electoral democracy, is particularly pronounced in the empirical literature. We reincorporate the role of civil liberties, which are at the core of modern democracy, in two ways. We identify four fundamental sources of potential differences in the evolution of political rights and civil liberties. We present systematic, robust and varied empirical evidence on the direct impact of two of these potential sources of differences using cross-national panel data and accounting for the modernization hypothesis. We obtain two noteworthy empirical results: civil liberties exhibit greater persistence than political rights in affecting subsequent outcomes; and, our main result, civil liberties are complementary to political rights when affecting subsequent outcomes, while the reverse is not the case. Consequently, one must incorporate civil liberties as a determinant of electoral democracy. More generally, both dimensions must be considered to understand the setbacks recently experienced by many democracies, despite their holding of free and fair elections.     

Debt enforcement,investment, and risk taking across countries

We argue that the prospect of an imperfect enforcement of debt contracts in default reduces shareholder–debtholder conflicts and induces leveraged firms to invest more and take on less risk as they approach financial distress. To test these predictions, we use a large panel of firms in 41 countries with heterogeneous debt enforcement characteristics. Consistent with our model, we find that the relation between debt enforcement and firms’ investment and risk depends on the firm-specific probability of default. A differences-in-differences analysis of firms’ investment and risk taking in response to bankruptcy reforms that make debt more renegotiable confirms the cross-country evidence.