In recent years dramatic technology developments have exploited the development of better transmission media and allowed for broad internet penetration. This in turn has fostered the growth of IP telephony calls, i.e., Voice over IP (VoIP). New VoIP products are introduced almost daily, each seeking an opportunity in the market. Some of these products are free - thus putting pressure on other vendors. A good example of a commercial VoIP product is Skype. It is possibly the most important one as it has gained more than 3 millions users in approximately 2 years time. In contrast, Minisip is a non-commercial implementation of SIP developed by students at KTH. These programs are based on different architectures. While Skype is said to be based on a peer-to-peer protocol, Minisip utilized the Session Initiation Protocol (SIP) protocol. The aim of this thesis was to evaluate these two VoIP programs not only in terms of development, but also in terms of the quality of service and user perceived voice quality. The study of efficiency, usability, and installation of both are also in the scope of this thesis. The devices used for the evaluation included a HP iPAQ 5550, two PCs running in RedHat Linux 9, and a laptop running Microsoft Windows XP. / På senare år har den dramatiska teknikutvecklingen exploaterat utvecklingen av bättre överföringsmedia samt möjliggjort för en bred Internetpenetrering. Det i sin tur har gynnat ökningen av telefonsamtal med IP-telefoner, d.v.s. Voice over IP (VoIP). Nya VoIP produkter introduceras nästan dagligen och varje produkt söker sin möjlighet på marknaden. Vissa av dessa produkter är gratis och sätter alltså press på andra försäljarna. Ett bra exempel på en VoIP produkt är Skype. Det är möjligtvis den viktigaste produkten då den har fått tre miljoner användare på ungefär två års tid. I kontrast till detta finns Minisip som är en icke kommersiell implementation av SIP, utvecklad av studenter från KTH. Dessa program är baserade på olika arkitekturer. Medan Skype är baserat på ett peer-to-peer protokoll, utnyttjar Minisip protokollet Session Initiation Protocol (SIP) Protocol. Syftet med denna avhandling var att evaluera dessa två VoIP program, inte bara i termer av utveckling utan också i termer av ”quality of service” och hur användaren uppfattar röstkvaliteten. Studien innefattar också effektivitet, användarvänlighet och installation av de båda programmen. Enheterna som användes under denna evaluering var en HP iPAQ 5550, två pc:s med Linux Red Hat 9 samt en bärbar pc med Windows XP.

Despite the growing body of research in related disciplines, including economics, management, politics, psychology, and sociology, marketing research has largely overlooked the downstream consequences of economic inequality, despite its undeniable impact on individuals' consumption decisions and experiences. This dissertation endeavors to bridge this knowledge gap by uncovering two novel consumer consequences of economic inequality. To accomplish this, it draws upon a diverse range of data sources, including individual-level experimental and survey data, as well as aggregate-level transaction and census data. Additionally, it examines economic inequality across multiple levels, encompassing communities, counties, states, and countries, and operationalizes it both as objective and perceived economic inequality. In Essay 1, I investigate how economic inequality in a consumer's region affects their access to peer-to-peer (P2P) services. Across diverse types of P2P services, I find convergent evidence that increased economic inequality in a consumer's region reduces providers' willingness to serve them, ultimately resulting in their diminished access to P2P services. This adverse effect of economic inequality can be attributed to providers perceiving consumers from more unequal regions as less trustworthy. This perception leads them to perceive heightened financial risks associated with serving these consumers. Moreover, this negative impact of economic inequality attenuates when providers perceive greater interpersonal similarity with consumers from unequal regions. In Essay 2, I explore how economic inequality within one's society affects their education decisions through the lens of perceived education premium. Firstly, it encourages people to attend college as it amplifies the perceived education premium of college—the income gap between college graduates and high school graduates. Secondly, it motivates people to choose majors with higher earning potential but lower personal interests, as opposed to those that align more with their genuine interests but pay less. This shift towards prioritizing extrinsic motivations over intrinsic ones is driven by people's perception of a more significant education premium between majors—the income disparity between higher-paying and lower-paying majors. / Doctor of Philosophy / Economic inequality, defined as the unequal distribution of income among various groups in a society, has been on the rise globally in recent decades. Amid the growing economic inequality, researchers have been delving into its profound impacts on individuals across diverse domains, exploring its influences on their mindsets, perspectives on the world, social lives, and overall well-being. It's surprising that there has been relatively little research on how economic inequality affects people's consumption decisions and experiences, given its undeniable influence on them. In this dissertation, I explore the impacts of economic inequality on consumers' access to P2P services and education decision-making. In Essay 1, I investigate how economic inequality in a consumer's region affects their access to peer-to-peer (P2P) services. I examine whether P2P providers are equally willing to serve consumers from regions with varying levels of economic inequality. I reveal a disconcerting reality: providers are less willing to offer P2P services to consumers from more unequal regions, driven by the perception of these consumers as less trustworthy and posing a higher financial risk. These differing attitudes ultimately lead to reduced access to P2P services and region-based discrimination for consumers from regions characterized by higher economic inequality. Fortunately, these adverse outcomes can be mitigated by an increase in perceived interpersonal similarity between providers and consumers. In Essay 2, I investigate how economic inequality in one's society shapes their education decisions. I find that as economic inequality rises, people become more willing to pursue a college education because they perceive a wider income gap between well-educated individuals and those with lower levels of education. Besides college decisions, economic inequality also influences people's choice of major for a similar reason. In a society characterized by greater economic inequality, people gravitate towards majors that promise higher earning potential, even if these fields do not align closely with their personal interests. This preference is driven by their perception of a greater wage difference between higher- and lower-paying majors. These findings provide policy implications for several pressing challenges in higher education.