Established in 2006, TATA Africa Services (Nigeria) Limited operates as the nodal point for Tata businesses in West Africa. TATA Africa Services (Nigeria) Limited has a strong presence in Nigeria with investments exceeding USD 10 million. The company was established in Lagos, Nigeria as a subsidiary of TATA Africa Holdings (SA) (Pty) Limited, South Africa and serves as the hub of Tata’s operations in Nigeria and the rest of West Africa.

What About Us

Using various methods, the size of the shadow economy in 76 developing, transition, and OECD countries is estimated. Average size varies from 12 percent of GDP for OECD countries, to 23 percent for transition countries and 39 percent for developing countries. Increasing taxation and social security contributions combined with rising state regulations are driving forces for the increase of the shadow economy, especially in OECD countries. According to some findings, corruption has a positive impact on the size of the shadow economy, and a growing shadow economy has a negative effect on official GDP growth.

/pdf/shadow-economies-size-causes-and-consequences-1rnohp2zuz.pdf

Shadow Economies: Size, Causes, and Consequences

The 5th generation (5G) of mobile networks is just around the corner. It is expected to bring extraordinary benefits to the population and to solve the majority of the problems of current 4th generation (4G) systems. The success of 5G, whose first phase of standardization has concluded, relies in three pillars that correspond to its main use cases: massive machine-type communication (mMTC), enhanced mobile broadband (eMBB), and ultra-reliable low latency communication (URLLC). This thesis mainly focuses on the first pillar of 5G: mMTC, but also provides a solution for the eMBB in massive content delivery scenarios. Specifically, its main contributions are in the areas of: 1) efficient support of mMTC in cellular networks; 2) random access (RA) eventreporting in wireless sensor networks (WSNs); and 3) cooperative massive content delivery in cellular networks. RegardingmMTC in cellular networks, this thesis provides a thorough performance analysis of the RA procedure (RAP), used by the mobile devices to switch from idle to connected mode. These analyses were first conducted by simulation and then by an analytical model; both of these were developed with this specific purpose and include one of the most promising access control schemes: the access class barring (ACB). To the best of our knowledge, this is one of the most accurate analytical models reported in the literature and the only one that incorporates the ACB scheme. Our results clearly show that the highly-synchronized accesses that occur in mMTC applications can lead to severe congestion. On the other hand, it is also clear that congestion can be prevented with an adequate configuration of the ACB scheme. However, the configuration parameters of the ACB scheme must be continuously adapted to the intensity of access attempts if an optimal performance is to be obtained. We developed

A Ph.D. Thesis

Four alternative but related approaches to empirical evaluation of policy interventions are studied: social experiments, natural experiments, matching methods, and instrumental variables. In each case the necessary assumptions and the data requirements are considered for estimation of a number of key parameters of interest. These key parameters include the average treatment effect, the treatment of the treated and the local average treatment effect. Some issues of implementation and interpretation are discussed drawing on the labour market programme evaluation literature.

Alternative approaches to evaluation in empirical microeconomics

https://www.econstor.eu/bitstream/10419/21855/1/dp2004-16.pdf

Shadow economies around the world: what do we really know?

In this volume we report the results of an extensive empirical study into the size of the Canadian underground economy, its development from the mid-1970's to the mid-1990's, and some of the linkages between taxation policy and underground activity in this country. First, we estimate that the Canadian Underground Economy grew from about 3.5% of measured GDP in 1976, to almost 16% in 1995. The latter figure accords well with recent evidence for Canada obtained by Schneider by totally different means - he estimates that it averaged 14.8% in 1994/95 and 16.2% in 1997/98. Second, when the implications of an underground economy of this size are explored in terms of the amount of tax revenue that is lost, we find that the size of this "tax-gap" varied from approximately $2 billion in 1976 to almost $44 billion in 1995, in current-dollar terms. Third, we establish a clear and positive empirical relationship between the aggregate effective tax rate and the (relative) size of the underground economy. We have shown that there is significant statistical evidence of two-way Granger causality, both from the effective tax rate, to the underground economy; and also from the underground economy to the effective tax rate.

Taxes and the Canadian underground economy

There is considerable agreement internationally about the factors that determine the relative size of the underground economy (tax burden, regulation, enforcement, confidence in government, labour force characteristics, and morality) and that evidence of underground activity will be captured in several economic indicators (GDP, currency in circulation, and consumption rates). Until recently, however, the methods that have been employed to measure the underground economy focused on only a few causal factors, one indicator, and only produced an estimate for one particular point in time. There exists a modeling technique that treats the underground economy as an unobservable or latent variable and incorporates multiple indicator and multiple causal (MIMIC) variables. The MIMIC model uses information contained within relevant indicator and causal variables to estimate a time-path of the size of the hidden economy. In applying this estimation technique to Canada data, my results indicate that, the underground economy in Canada grew steadily relative to measured GDP over the period 1976 to 2001. The value of the broadly defined underground economy grew from about 7.5% of GDP in 1976 to about 15.3% in 2001. In real (1997) dollar terms, it increased from about $38 billion to $159 billion.

/pdf/the-underground-economy-in-canada-4grl3fe471.pdf

The Underground Economy in Canada

This paper uses a unique and recently available dataset that contains detailed information on firms from around the world to investigate factors that affect under-reporting behaviour by firms. The empirical strategy employed exploits the nature of the dependent variable, which is interval coded, and uses interval regression which provides an asymptotically more efficient estimator than the ordered probit, provided that the classical linear model assumptions hold. These assumptions are investigated using standard diagnostic tests that have been modified for the interval regression model. Evidence is presented that shows that firms in all regions around the world engage in under-reporting. Regression results indicate that government corruption has the single largest causal effect on under-reporting, resulting in the percentage of sales not reported to the tax authority being 53.4 percent higher. Taxes have the second single largest causal effect on under-reporting, resulting in the percentage of sales not reported to the tax authority being 20.2 percent higher. Access to financing, organized crime, political instability and the fairness of the legal system were found to have no effect on under-reporting. It is also found that there is a significant correlation between under-reporting and the legal organization of the business, size, age, ownership, competition and audit controls.

Keeping it Off the Books: An Empirical Investigation of Firms that Engage in Tax Evasion

Using new time-series data for the size of the Canadian underground economy, we examine the relationship between unreported and measured GDP in that country. Granger causality tests are conducted, with a proper allowance for the non-stationarity of the data. We find that there is clear evidence of such causality from measured GDP to "hidden" output, but only very mild evidence of Granger causality in the reverse direction. This result supports similar evidence for New Zealand reported by the first author, and has several interesting policy implications.

The Canadian Underground and Measured Economies: Granger Causality Results

There is considerable interest in measuring tax noncompliance using microeconomic data. One such method estimates income under-reporting by self-employed households by assuming a known, parametric form of the Engel curve and making the further parametric assumption that self-employed households under-report their income by a constant fraction, independent of income. This paper proposes a nonparametric approach which avoids functional form restrictions and allows the form of the reporting function to be uncovered rather than being imposed a priori. The approach is illustrated by estimating the effect of the Canadian Goods and Services Tax on income under-reporting by a sample of self-employed households.

Estimating the Income Reporting Function for the Self-Employed

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Lindsay M. Tedds

Author Tools

Chat about Author