Land use and land cover scenarios: An interdisciplinary approach integrating local conditions and the global shared socioeconomic pathways

Land Use and Land Cover (LULC) changes have profound impacts on the functioning of (agro)ecosystems and have potential to mitigate global climate change. However, we still lack interdisciplinary methods to project future LULC scenarios at spatial scales that are relevant for local decision making and future environmental assessments. Here we apply an interdisciplinary approach to develop spatially explicit projections of LULC at a resolution of 30 × 30 m informed by historic relationships between LULC and their key drivers, within the context of the four qualitative scenarios of global shared socioeconomic pathways. We apply this methodology to a case study in the Zona da Mata, Brazil, which has a history of major LULC changes. The analysis of LULC changes from 1986 to 2015 indicates that pasture area decreased from 76 to 58 % of total area, while forest areas increased from 18 to 24 %, and coffee from 3 to 11 %. Environmental protection legislation, rural credit for smallholder farmers, and demand for agricultural and raw products were identified as main drivers of LULC changes. Projected LULC for 2045 strongly depends on the global socioeconomic pathway scenarios, and forest and coffee areas may increase substantially under strong government measures in the environmentally conscious Green Road scenario or decrease in the high consumption Rocky Road scenario. Our study shows that under the set of drivers during the past three decades reforestation can go hand in hand with increase of agricultural production, but that major and contrasting changes in LULC can be expected depending on the socioeconomic pathway that will be followed in the future. To guide this process, LULC scenarios at the local scale can inform the planning of local and regional development and forest conservation.     

Rural Residential Land Transition in the Beijing-Tianjin-Hebei Region: Spatial-Temporal Patterns and Policy Implications

Rural residential land transition (RRLT) dominates rural land use transition. Therefore, analysing the laws of transition and differentiation of land use is not only the basis for the differential management of rural residential areas but key to the sustainable use of rural land. This study constructs a conceptual model of RRLT using multi-period remote sensing monitoring data based on a comprehensive index method, ArcGIS, and FRAGSTATS landscape pattern analysis, among others. It also analyses the characteristics of the transition extent, transition trend, transition morphology, and transition intensity of rural residential land in the Beijing-Tianjin-Hebei (BTH) region from 1980 to 2018. The results show that, from a vertical comparison of long time series, the transition extent is characterised by a process of ‘slow growth—expanding start—fast expansion—slowing down’; the transition trend is characterised by an increase in the amount of cultivated land occupied by rural residential land, followed by a large number of rural residential land is reclaimed as cultivated land; the transition morphology is characterised by an increase in mean patch size and degree of irregularity, as well as aggregation; and the transition intensity is characterised by fluctuations in the process of ‘small-scale reduction—small-scale growth—substantial growth—small-scale growth and reduction’. A horizontal comparison of counties in the BTH region reveals a long-lasting and active growth trend in transition extent and transition intensity in the Beijing-Tianjin region, and a gradually slowing trend in the areas around the region. The transition morphology features of the northwest Hebei region are more prominent, and show that the scale of rural settlements is small, the plaques fragmented and irregular, and the layout more scattered. The BTH region should formulate a differentiated transition direction for rural residential areas based on the different functional areas, and play into the agglomeration, scale, and synergy effects of urban agglomerations. It should also coordinate and improve the human–land relationship in rural areas, and construct an orderly and densely distributed pattern of urban and rural spatial development with a reasonable layout and complementary functions.     

Demographic Transition and Fertility Rebound in Economic Development*

Recent evidence on the “fertility rebound” offers credence to the idea that, from the onset of early industrialization to the present day, the dynamics of fertility can be represented by an N-shaped curve. An overlapping generations model with parental investment in human capital can account for these observed movements in fertility rates during the different stages of demographic change. A demographic transition with declining fertility emerges at the intermediate stage, when parents engage on a child quantity–quality trade-off. At later stages, however, the process of economic growth generates sufficient resources so that households can rear more children while still providing the desirable amount of education investment per child.     

Modeling the time varying volatility of housing returns: Further evidence from the U.S. metropolitan condominium markets

This study extends the literature on modeling the volatility of housing returns to the case of condominium returns for five major U.S. metropolitan areas (Boston, Chicago, Los Angeles, New York, and San Francisco). Through the estimation of ARMA models for the respective condominium returns, we find volatility clustering of the residuals. The results from an ARMA‐TGARCH‐M model reveal the absence of asymmetry in the conditional variance. Dummy variables associated with the housing market collapse unique to each metropolitan area were statistically insignificant in the conditional variance equation, but negative and statistically significant in the mean equation. Condominium markets in Los Angeles and San Francisco exhibit the greatest persistence to volatility shocks.     

Pairs trading strategies in a cointegration framework: back-tested on CFD and optimized by profit factor

Statistical arbitrage is based on pairs trading of mean-reverting returns. We used cointegration approach and ECM-DCC-GARCH to construct 98 pairs of 152 stocks of 3 currencies. Stocks trading is done by Contract for Difference (CFD), a financial derivative product which facilitates short selling and provides a leverage up to 25 times. To measure the performance of a leveraged strategy, we introduced the profit factor which is the annualized return rate per unit risk. And the historical risk is measured by maximum drawdown. We compared three main strategies: percentage, standard deviation of cointegration long-term residuals and Bollinger Bands (dynamic standard deviation), with and without double confirmation of short-term standard deviation modelled by ECM-DCC-GARCH. Each of the three main strategies is optimized by two optimizers: absolute profit and profit factor. The optimization period goes from 2012–01-01 to 2014–12-31, and validation period is from 2015–01-01 to 2016–06-01. Our results showed that the USD Bollinger Bands strategy without double confirmation and optimized by profit factor, outperformed other strategies and provided the highest annualized return rate per unit risk; 32% of our sample pairs ended up in loss, and 94% of which are explained by a cointegration break during the testing period.     

Variance swaps valuation under non-affine GARCH models and their diffusion limits

In this article, we investigate the pricing and convergence of general non-affine non-Gaussian GARCH-based discretely sampled variance swaps. Explicit solutions for fair strike prices under two different sampling schemes are derived using the extended Girsanov principle as the pricing kernel candidate. Following standard assumptions on time-varying GARCH parameters, we show that these quantities converge respectively to fair strikes of discretely and continuously sampled variance swaps that are constructed based on the weak diffusion limit of the underlying GARCH model. An empirical study which relies on a joint estimation using both historical returns and VIX data indicates that an asymmetric heavier tailed distribution is more appropriate for modelling the GARCH innovations. Finally, we provide several numerical exercises to support our theoretical convergence results in which we further investigate the effect of the quadratic variation approximation for the realized variance, as well as the impact of discrete versus continuous-time modelling of asset returns.     

Trade and dietary diversity in Eastern Europe and Central Asia

In public and academic debates, the linkages between agricultural markets and nutrition across the world are vividly discussed. This paper contributes to the ongoing debate by analyzing the relationship between greater openness to trade and dietary diversity. It focuses on the post-communist countries of Eastern Europe and Central Asia where trade reforms triggered growth in trade flows and foreign direct investment, which in turn affected food systems in these countries. This shift provides a natural experiment for studying the effects of trade openness on agricultural markets and consumer behaviour. Reduction in trade barriers, for instance in the context of the accession to the WTO and the EU, and the gradual integration with world markets after 1991 had implications for diets through changes in production, prices and incomes. We utilize country-level panel data for 26 post-communist countries in the period 1996–2013 to assess the effects of trade costs, agricultural trade openness and incomes on dietary diversity measured by the Shannon entropy index. The results from fixed effects and instrumental variables estimation are consistent with previous findings that income growth affects dietary diversity positively. They also provide novel evidence that trade barriers reduce variety of products available in domestic markets, in particular fruits and vegetables.     

关于公路与桥梁之间过渡段施工技术初探

本文主要分析了公路桥梁间过渡段出现不均沉降的原因以及公路桥梁间过渡段的施工技术的应用情况,此项技术对降低施工成本,提升桥梁的可靠性与安全性有重要作用。     

INVESTMENT BEHAVIOUR,CORPORATE CONTROL,AND PRIVATE BENEFITS OF CONTROL: EVIDENCE FROM A SURVEY OF UKRAINIAN FIRMS

We analyse the impact of ownership and corporate control on firms’ investment using the 2001 survey of Yacoub et al. on Ukrainian firms. The model explains investment by output, financial and soft budget constraints, and corporate control (and ownership) categories potentially enjoying private benefits of control. We find that the corporate control model fits better than the ownership model, a negative relationship between state and employee control and firms’ investment, and evidence for the presence of soft budget constraints. A negative relationship between firms’ investment and the relative size of non‐monetary transactions strengthens the conclusion of private benefits of control impacting investment.     

TFP growth in Chinese cities: The role of factor-intensity and industrial agglomeration

This article estimates agglomeration effects via calculating EG (Elilsion & Glaeser) and TFP growth (Total Factor Production) by considering the undesired output of the industrial enterprise database and the entropy weight method. Using panel data of 207 county-level cities in China and 28 two-digit manufacturing industries from 2003 to 2013 based on SIC codes, this paper analyzes the relationship between agglomeration and TFP growth through the smooth transition model under different regions and factor-intensity. The results are as follows. (1) A negative relationship appears in manufacturing productivity. The agglomeration effect changes to the crowded effect. Environmental pollution is also generated by transportation and inadequate pollution treatment technology. (2) The excessive agglomeration phenomenon of developed areas (eastern region) is less than the less developed areas (central and western regions). (3) Resource-intensity industries present two thresholds that indicate complex regional features. For various intensive industries in different regions, the relationship between GML and agglomeration is different. High agglomeration does not always promote TFP growth. (4) At different levels of urban industrial agglomeration, the influences of efficiency change and technical change on GML are different. Overall, moderate agglomeration in all regions helps promote economic development.