Rebalancing frequency and the welfare cost of inflation

WOS:000302552800006Cash-in-advance models usually require agents to reallocate money and bonds in fixed periods. Every month or quarter, for example. I show that fixed periods underestimate the welfare cost of inflation. I use a model in which agents choose how often they exchange bonds for money. In the benchmark specification, the welfare cost of 10 percent instead of 0 inflation increases from 0.1 percent of income with fixed periods to 1 percent with optimal periods. The results are robust to different preferences, to different compositions of income in bonds or money, and to the introduction of capital and labor.publishersversionpublishe

Managerial ability and capital flows

WOS:000279138800010Capital flows with low intensity and flows to middle-income countries. Physical and human capital alone cannot explain this pattern. I present a model to show how managerial ability the ability to run risky projects can increase total factor productivity and explain the pattern of capital flows. The model implies that countries with more high-ability managers use more risky projects and have higher productivity. I define proxies for managerial ability with data on physical and human capital, schooling, and entrepreneurship. Consistent with the pattern of capital flows, the model predicts similar returns to capital across countries and higher returns in middle-income countries. (C) 2009 Elsevier B.V. All rights reserved.authorsversionpublishe

Taxes and labor supply: Portugal, Europe, and the United States (Conference version)

I relate hours worked with taxes on consumption and labor. I propose a model and compare its predictions for Portugal, France, Spain, United Kingdom and United States. Hours per worker in Portugal decreased from 35.1 in 1986 to 32.6 in 2001. With only the parameters and the taxes for Portugal, the model predicts the hours worked in 2001 with an error of only 12 minutes from the actual hours. Across countries, most predictions differ from the data by one hour or less. The model is able to explain the trend in hours with only the changes in taxes

Rebalancing frequency and the welfare cost of inflation

Cash-in-advance models usually require agents to reallocate money and bonds in fixed periods, every month or quarter, for example. I show that fixed periods underestimate the welfare cost of inflation. I use a model in which agents choose how often they exchange bonds for money. In the benchmark specification, the welfare cost of ten percent instead of zero inflation increases from 0.1 percent of income with fixed periods to one percent with optimal periods. The results are robust to different preferences, to different compositions of income in bonds or money, and to the introduction of capital and labor

Individual and aggregate money demands

I construct a model in which money and bond holdings are consistent with individual decisions and aggregate variables such as production and interest rates. The agents are infinitely-lived, have constant-elasticity preferences, and receive a fraction of their income in money. Each agent solves a Baumol-Tobin money management problem. Markets are segmented because financial frictions make agents trade bonds for money at different times. Trading frequency, consumption, government decisions and prices are mutually consistent. An increase in inflation, for example, implies higher trading frequency, more bonds sold to account for seigniorage, and lower real balances.INOVA, FC

Sub-Optimality of the Friedman Rule with Distorting Taxes

We find that the Friedman rule is not optimal with government transfers and distortionary taxation. This result holds for heterogeneous agents, standard homogeneous preferences, and constant returns to scale production functions. The presence of transfers changes the standard optimal taxation result of uniform taxation. As transfers cannot be taxed, a positive nominal net interest rate is the indirect way to tax the additional income derived from transfers. The higher the transfers, the higher is the optimal inflation rate. We calibrate a model with transfers to the US economy and obtain optimal values for inflation substantially above the Friedman rule.N/

A new concept of automated manufacturing process for wire rope terminals

30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) 15-18 June 2021, Athens, Greece.The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples).The authors would like to thank Mr. Mário Cardoso for his support and commitment with this work, providing all data necessary to carry out this development. The authors would like to acknowledge financial support from Fundação para a Ciência e Tecnologia (grants: UID/EMS/00667/2019 and UID/UIDB/CPO/04058/2020info:eu-repo/semantics/publishedVersio

Graphs with at most one crossing

The crossing number of a graph $G$ is the least number of crossings over all possible drawings of $G$. We present a structural characterization of graphs with crossing number one

Optical clearing methods: An overview of the techniques used for the imaging of 3D spheroids

Spheroids have emerged as in vitro models that reproduce in a great extent the architectural microenvironment found in human tissues. However, the imaging of 3D cell cultures is highly challenging due to its high thickness, which results in a light-scattering phenomenon that limits light penetration. Therefore, several optical clearing methods, widely used in the imaging of animal tissues, have been recently explored to render spheroids with enhanced transparency. These methods are aimed to homogenize the microtissue refractive index (RI) and can be grouped into four different categories, namely (a) simple immersion in an aqueous solution with high RI; (b) delipidation and dehydration followed by RI matching; (c) delipidation and hyperhydration followed by RI matching; and (d) hydrogel embedding followed by delipidation and RI matching. In this review, the main optical clearing methods, their mechanism of action, advantages, and disadvantages are described. Furthermore, the practical examples of the optical clearing methods application for the imaging of 3D spheroids are highlighted.info:eu-repo/semantics/publishedVersio