Unbalanced partnership scheme between community plantation forest and company: study case in West Kotawaringin, Central Kalimantan, Indonesia

The changing regulation for community plantation forest (CPF) from social forestry point of view into a business-oriented context has no significant effects on its capital strengthening. Limited capital becomes an obstacle for farmers to develop the CPF area. It encourages the CPF to conduct a partnership scheme with the nearest company in its working area. The objectives of the research are to evaluate the partnership scheme and to make improvements from the evaluation results. The research method used is descriptive analysis and quantitative approach. The results show that many problems have been raised during the partnership implementation as farmers have no bargaining position, the company’s log price is not feasible, and no explanation on how the price is determined. The profit margin of the CPF is the lowest (Rp98,000/ton wood) or 11.8% among the parties involved in the wood plantation businesses. Therefore, the partnership scheme must be improved for better prosperity of CPF farmers through shifting from partnership CPF to self-sufficient CPF. This shifting provides a high bargaining position and better revenue for the CPF farmers.

Identification of house price bubbles using robust methodology: evidence from Polish provincial capitals

This article aims to check whether there has been a price bubble in the Polish major housing markets in recent years. To accomplish this goal, the log price-to-rent ratios in Polish provincial cities were analysed. In order to avoid incorrect conclusions, the log price-to-rent ratio using the instrumental variable estimation and ordinary least squares methods was decomposed into two components: fundamental and non-fundamental. The latter was then examined using the Phillips, Shi, and Yu procedure to detect explosive and downward movements. The results of the study showed that, in general, over 2011, actual log price-to-rent ratios in the analysed cities were below their fundamental values, i.e., a negative price bubble existed. However, more or less since the beginning of 2013, the surveyed markets have seen an increasing level of the non-fundamental component of the index under study, and its particularly explosive movements are visible in the first quarters of 2014. Finally, this analysis indicated future research directions and study implications for Polish policy-makers, housing investors, and households.

The Price is Right: Predicting Reagent Prices

<div> <p>We present a model for estimating the price of a reagent from its chemical structure. It is intended to be useful when doing reagent selection for library design. The model is a Random Forest regressor which is trained on the MolPort catalog of 302K reagents and the log of their price. For descriptors we use topological fingerprints from RDKit: chiral Morgan fingerprints, its medicinal chemistry descriptors, and counts of undetermined chiral centers. The model has an out-of-bag performance of 34% variance explained in log Price. When predicting on known reagents, the model explains 91% of the variance in log Price. We analyzed the model to understand the errors that the model makes. We show that the compounds with the highest errors have only a subtly different structure from similar molecules, but very different in price. </p> </div>

The Price is Right: Predicting Reagent Prices

<div> <p>We present a model for estimating the price of a reagent from its chemical structure. It is intended to be useful when doing reagent selection for library design. The model is a Random Forest regressor which is trained on the MolPort catalog of 302K reagents and the log of their price. For descriptors we use topological fingerprints from RDKit: chiral Morgan fingerprints, its medicinal chemistry descriptors, and counts of undetermined chiral centers. The model has an out-of-bag performance of 34% variance explained in log Price. When predicting on known reagents, the model explains 91% of the variance in log Price. We analyzed the model to understand the errors that the model makes. We show that the compounds with the highest errors have only a subtly different structure from similar molecules, but very different in price. </p> </div>

Volatility Co-Movement in Stock Markets

The volatility and log-price collective movements among stocks of a given market are studied in this work using co-movement functions inspired by similar functions in the physics of many-body systems, where the collective motions are a signal of structural rearrangement. This methodology is aimed to identify the cause of coherent changes in volatility or price. The function is calculated using the product of the variations in volatility (or price) of a pair of stocks, averaged over all pair particles. In addition to the global volatility co-movement, its distribution according to the volatility of the stocks is also studied. We find that stocks with similar volatility tend to have a greater co-movement than stocks with dissimilar volatility, with a general decrease in co-movement with increasing volatility. On the other hand, when the average volatility (or log-price) is subtracted from the stock volatility (or log-price), the co-movement decreases notably and becomes almost zero. This result, interpreted within the background of many body physics, allows us to identify the index motion as the main source for the co-movement. Finally, we confirm that during crisis periods, the volatility and log-price co-movement are much higher than in calmer periods.

Fast Hybrid Schemes for Fractional Riccati Equations (Rough Is Not So Tough)

We solve a family of fractional Riccati equations with constant (possibly complex) coefficients. These equations arise, for example, in fractional Heston stochastic volatility models, which have received great attention in the recent financial literature because of their ability to reproduce a rough volatility behavior. We first consider the case of a zero initial value corresponding to the characteristic function of the log-price. Then we investigate the case of a general starting value associated to a transform also involving the volatility process. The solution to the fractional Riccati equation takes the form of power series, whose convergence domain is typically finite. This naturally suggests a hybrid numerical algorithm to explicitly obtain the solution also beyond the convergence domain of the power series. Numerical tests show that the hybrid algorithm is extremely fast and stable. When applied to option pricing, our method largely outperforms the only available alternative, based on the Adams method.

The Value of Insight

An investor may invest in a riskless bank account and in a stock that is a standard Black–Scholes asset with occasional Gaussian jumps of the log price, as proposed by Merton [Merton RC ( 1976 ) Option pricing when underlying stock returns are discontinuous. J. Financial Econom. 3(1):125–144.]. It is well known how to solve the standard running consumption problem for this investor, which we take as a benchmark for comparing the performance of two different insiders, one who knows in advance of each jump exactly when the jump will happen, and the other who has information in advance of each jump about the size of the jump but no information about the time. These considerations give rise to two novel and concrete stochastic control problems. For each problem, rigorous verification proofs for optimality are presented.

The role of tropical abandoned land relative to ecological and economic aspects

The floristic structure and composition of abandoned lands in the tropic have been observed to be changing dynamically during the succession process. This is mostly because they are not utilized maximally, therefore, there is a need to assess the economic and ecological impacts of this land abandonment in tropical areas. This study was conducted to determine the ecological aspects of standstructure, floristic composition, and species diversity and analyze the economic aspects of standing trees in tropical abandoned land. The vegetation containing woody trees with a diameter at breast height (DBH) of > 5 cm were surveyed at six subplots sized 20 m × 20 m. The economic parameters were evaluated using data of log price, logging cost, profit margin, and stumpage value of standing trees in the study plot and a total of 126 trees including 26 species of 25 genera of 18 families were recorded. The most common species found were Macaranga tanarius with 50.60%, Bridelia glauca with 49.13%, and Pterospermum javanicum with 29.05% based on Importance Value Index (IVi). Moreover, the diversity, dominance, evenness, and richness indices were 1.23, 0.09, 0.87, and 5.17 respectively while the total log price at the abandoned land was 1,462.02 USD m-3 with an average value of 56.23USD m-3. The total and mean values of logging costs were 1,212.24USD ha-1 and 46.62USD ha-1, respectively while the total profit margin of log selling was USD337.39m-3 at maximum with an average of 12.98 USD m-3. Furthermore, the average stumpage value was 83.05 USD ha-1 while the total was calculated to be 2,159.36 USD ha-1.These findings showed the utilization of abandoned lands with respect to ecology and economic aspects has the ability to increase community welfare and support the implementation of developmental programs in the country.

Demonstrating the Effect of Height Variation on Stand-Level Optimization with Diameter-Structured Matrix Model

The weakness of the population matrix models is that they do not take into account the variation inside the class. In this study, we introduce an approach to add height variation of the trees to the diameter-structured matrix models. In this approach, a new sub-model that describes the height growth of the trees is included in the diameter-structured model. We used this height- and diameter-structured matrix model to maximize the net present value (NPV) for the remaining part of the ongoing rotation for Scots pine (Pinus sylvestris L.) stand and studied how the height variation affects to the results obtained through stand-level optimization. In the optimization, the height variation was taken into account by setting the lower saw-log price for the short trees. The results show that including the height variation into the optimization reduced the financial outcome by 16–18% and considerably changed the structure of optimal management (e.g., timings for thinnings, rotation period and intensity of thinnings). We introduced an approach that can be applied to include not only height variation but also variation of other tree properties (such as branchiness or the amount of heartwood and sapwood) into the matrix models.

Entropic Dynamics of Stocks and European Options

We develop an entropic framework to model the dynamics of stocks and European Options. Entropic inference is an inductive inference framework equipped with proper tools to handle situations where incomplete information is available. The objective of the paper is to lay down an alternative framework for modeling dynamics. An important information about the dynamics of a stock’s price is scale invariance. By imposing the scale invariant symmetry, we arrive at choosing the logarithm of the stock’s price as the proper variable to model. The dynamics of stock log price is derived using two pieces of information, the continuity of motion and the directionality constraint. The resulting model is the same as the Geometric Brownian Motion, GBM, of the stock price which is manifestly scale invariant. Furthermore, we come up with the dynamics of probability density function, which is a Fokker–Planck equation. Next, we extend the model to value the European Options on a stock. Derivative securities ought to be prices such that there is no arbitrage. To ensure the no-arbitrage pricing, we derive the risk-neutral measure by incorporating the risk-neutral information. Consequently, the Black–Scholes model and the Black–Scholes-Merton differential equation are derived.