A collaborative framework for browser games development

This dissertation describes a conceptual model and prototype for a collaborative framework for browser games development using open source and open content. There is an extensive literature review exploring several areas like game development, modding, open source software development, open content and creative commons. The most relevant ideas about game development and collaboration are then used in defining the conceptual model of the framework with the objective of facilitating community creation and collaboration. Finally the implementation of prototype is explained in detail and the practical difficulties in implementing the conceptual model are addressed. This research shows that a collaboration framework for creating open source and open content browser games is possible and paves way for future studies about the community creation in this type of collaborative systems.Esta dissertação descreve um modelo conceptual e um protótipo de um sistema colaborativo para o desenvolvimento de jogos no browser utilizando código aberto e conteúdos abertos. É feita uma revisão extensiva da literatura em várias áreas como desenvolvimento de jogos, modding, desenvolvimento de software open source, conteúdos abertos e Creative Commons. As ideias mais importantes acerca do desenvolvimento de jogos, conteúdos e colaboração são usadas para definir um modelo conceptual do sistema com o objectivo de facilitar a colaboração e criação de uma comunidade forte. Finalmente a implementação de um protótipo do sistema é explicada em detalhe e são referidas as principais dificuldades práticas na implementação do modelo conceptual. Esta pesquisa mostra que é possível criar um sistema colaborativo para a criação de jogos como código e conteúdos abertos e abre caminho para futuros estudos sobre a criação de comunidades neste tipo de sistemas colaborativos

The impact individualized instruction with learning technologies has on student achievement: New directions for at-risk students with college aspirations

The purpose of the study is to measure the benefits of a remedial low-track academic program that includes individualized instruction using learning technologies by comparing the 9th grade Explore, 10th grade Plan, and 11th grade ACT standardized tests scores as a measure of academic achievement in English, mathematics, reading, and scientific reasoning. A second purpose is to determine if there is a difference in academic achievement between male and female students that have experienced the same curriculum in a co-institutional single-sex schooling environment. The standardized test scores of male and female students from the class of 2007, the treatment group, are compared to the students in the class of 2006, the control group. There are 51 male and female students in the class of 2007, and 47 male and female students in the class of 2006. Although the students are at-risk of dropping out of high school due to low levels of educational attainment, they have college aspirations, and students who have graduated ahead of them have enrolled in post-secondary educational institutions. The students are African American, Latino/a, and European American and attend a private, religious high school in an urban environment. The analyses of the results reveal significant differences in scientific reasoning achievement for male students from 9th to 11th grade. There are mixed findings in English, mathematics, and reading that can be attributed to the curricular flexibility afforded in a co-institutional educational model. Although there was some lack of standardization of instruction in implementing the curriculum between the two campuses, no significant differences were found between the male and female students in the class of 2007

Conformity Hinders the Evolution of Cooperation on Scale-Free Networks

We study the effects of conformity, the tendency of humans to imitate locally common behaviors, in the evolution of cooperation when individuals occupy the vertices of a graph and engage in the one-shot Prisoner's Dilemma or the Snowdrift game with their neighbors. Two different graphs are studied: rings (one-dimensional lattices with cyclic boundary conditions) and scale-free networks of the Barabasi-Albert type. The proposed evolutionary-graph model is studied both by means of Monte Carlo simulations and an extended pair-approximation technique. We find improved levels of cooperation when evolution is carried on rings and individuals imitate according to both the traditional pay-off bias and a conformist bias. More important, we show that scale-free networks are no longer powerful amplifiers of cooperation when fair amounts of conformity are introduced in the imitation rules of the players. Such weakening of the cooperation-promoting abilities of scale-free networks is the result of a less biased flow of information in scale-free topologies, making hubs more susceptible of being influenced by less-connected neighbors.Comment: 14 pages, 11 figure

Empirical econometric evaluation of alternative methods of dealing with missing values in investment climate surveys

Investment climate Surveys are valuable instruments that improve our understanding of the economic, social, political, and institutional factors determining economic growth, particularly in emerging and transition economies. However, at the same time, they have to overcome some difficult issues related to the quality of the information provided; measurement errors, outlier observations, and missing data that are frequently found in these datasets. This paper discusses the applicability of recent procedures to deal with missing observations in investment climate surveys. In particular, it presents a simple replacement mechanism -- for application in models with a large number of explanatory variables -- which in turn is a proxy of two methods: multiple imputations and an export-import algorithm. The performance of this method in the context of total factor productivity estimation in extended production functions is evaluated using investment climate surveys from four countries: India, South Africa, Tanzania, and Turkey. It is shown that the method is very robust and performs reasonably well even under different assumptions on the nature of the mechanism generating missing data.E-Business,Statistical&Mathematical Sciences,Economic Theory&Research,Information Security&Privacy,Information and Records Management

Assessing the impact of infrastructure quality on firm productivity in Africa : cross-country comparisons based on investment climate surveys from 1999 to 2005

This paper provides a systematic, empirical assessment of the impact of infrastructure quality on the total factor productivity (TFP) of African manufacturing firms. This measure is understood to include quality in the provision of customs clearance, energy, water, sanitation, transportation, telecommunications, and information and communications technology (ICT). Microeconometric techniques to investment climate surveys (ICSs) of 26 African countries are carried out in different years during the period 2002–6, making country-specific evaluations of the impact of investment climate (IC) quality on aggregate TFP, average TFP, and allocative efficiency. For each country the impact is evaluated based on 10 different productivity measures. Results are robust once controlled for observable fixed effects (red tape, corruption and crime, finance, innovation and labor skills, etc.) obtained from the ICSs. African countries are ranked according to several indices: per capita income, ease of doing business, firm perceptions of growth bottlenecks, and the concept of demeaned productivity (Olley and Pakes 1996). The countries are divided into two blocks: high-income-growth and low-income-growth. Infrastructure quality has a low impact on TFP in countries of the first block and a high (negative) impact in countries of the second. There is significant heterogeneity in the individual infrastructure elements affecting countries from both blocks. Poor-quality electricity provision affects mainly poor countries, whereas problems dealing with customs while importing or exporting affects mainly faster-growing countries. Losses from transport interruptions affect mainly slower-growing countries. Water outages affect mainly slower-growing countries. There is also some heterogeneity among countries in the infrastructure determinants of the allocative efficiency of African firms.Transport Economics Policy&Planning,Economic Theory&Research,E-Business,Labor Policies,Infrastructure Economics

Assessing the impact of infrastructure quality on firm productivity in Africa: Cross-country comparisons based on investment climate surveys from 1999 to 2005

This paper provides a systematic, empirical assessment of the impact of infrastructure quality on the total factor productivity (TFP) of African manufacturing firms. This measure is understood to include quality in the provision of customs clearance, energy, water, sanitation, transportation, telecommunications, and information and communications technology (ICT). We apply microeconometric techniques to investment climate surveys (ICSs) of 26 African countries carried out in different years during the period 2002–6, making country-specific evaluations of the impact of investment climate (IC) quality on aggregate TFP, average TFP, and allocative efficiency. For each country we evaluated this impact based on 10 different productivity measures. Results are robust once we control for observable fixed effects (red tape, corruption and crime, finance, innovation and labor skills, etc.) obtained from the ICSs. We ranked African countries according to several indices: per capita income, ease of doing business, firm perceptions of growth bottlenecks, and the concept of demeaned productivity (Olley and Pakes 1996). We divided countries into two blocks: high-incomegrowth and low-income-growth. Infrastructure quality has a low impact on TFP in countries of the first block and a high (negative) impact in countries of the second. We found heterogeneity in the individual infrastructure elements affecting countries from both blocks. Poor-quality electricity provision affects mainly poor countries, whereas problems dealing with customs while importing or exporting affects mainly faster-growing countries. Losses from transport interruptions affect mainly slower-growing countries. Water outages affect mainly slower-growing countries. There is also some heterogeneity among countries in the infrastructure determinants of the allocative efficiency of African firms.Africa, Infrastructure, Total factor productivity, Investment climate, Competitiveness,

Investment climate assessment based on demean Olley and Pakes decompositions: methodology and application to Turkey's investment climate survey

Most empirical studies show strong detrimental evidence that regulatory, and administrative, barriers to entry have on productivity and on firm growth. In this paper we evaluate and measure the total factor productivity (TFP) impacts of having; low quality physical infrastructures (electricity, telecommunications, transport, customs, etc.) and bad social infrastructures (rules of law, informality, corruption, etc.). We suggest evaluating the impact on average productivity (TFP) and on the allocative efficiency of production among firms based on several versions of the Olley and Pakes (O&P) decompositions. We evaluate the advantages and disadvantages of each the O&P decomposition in terms of their IC explanatory power. Once we have measured those IC impacts, we compare them with other sources of empirical information obtained from firm’s perceptions on main bottlenecks for firm growth and from doing business reports of the World Bank (2007). For the econometric analysis, we use firm level data bases from Turkey’s manufacturing sector based on Investment Climate surveys (ICs) done by the World Bank. These ICs are done in many other developing countries and therefore we propose to make crosscountry comparisons based on a new demean concept of TFP that also reduces the heterogeneity if using several robust productivity measures within each country

Investment climate and firm’s economic performance: econometric methodology and application to Turkey's investment climate survey

Government policies and behavior exert a strong influence on the investment climate through their impact on costs, risks and barriers to competition. Key factors affecting the investment climate through their impact on costs are: corruption, taxes, the regulatory burden and extent of red tape in general, factor markets (labor, intermediate materials and capital), the quality of infrastructure, technological and innovation support, and the availability and cost of finance. While the investment climate surveys are quite useful in identifying major issues and bottlenecks as perceived by firms, the data collected is also meant to provide the basic information for an econometric assessment of the impact or contribution of the investment climate (IC) variables on productivity. We believe that improving the investment climate (IC) is a key policy instrument to promote economic growth and to mitigate the institutional, legal, economic and social factors that are constraining the convergence of per capita income and labor productivity of Turkey relative to more developed countries. For that, we need to identify the main investment climate variables that affect economic performance measures like total factor productivity, employment, wages, exports and foreign direct investment and this is the main goal of this paper. In turn, that quantified impact is used in the advocacy for, and design of, investment-climate reforms

Empirical econometric evaluation of alternative methods of dealing with missing values in Investment Climate surveys

The Investment Climate surveys (ICSs) are valuable instruments which improve our understanding of the economic, social, political and institutional factors determining economic growth, particularly in emerging and transition economies. However, at the same time, they have to overcome some difficult issues related with the quality of the information provided; measurement errors, outlier observations and missing data are frequently found in this datasets. In this paper we discuss the applicability of recent procedures to deal with missing observations in IC surveys. In particular we present a simple replacement mechanism—for application in models with a large number of explanatory variables—, which we call the ICA method, which in turn is a proxy of two methods: multiple imputation and EM algorithm. We evaluate the performance of this ICA method in the context of TFP estimation in extended production functions using ICSs from four countries: India, South Africa, Tanzania and Turkey. We find that the ICA method is very robust and performs reasonably well even under different assumptions on the nature of the mechanism generating missing data