The last two decades have seen the autofiction novel become a cultural hegemon in North American and European literature. While many scholars have argued that the form's popularity is purely the result of an aesthetic turn away from postmodernism towards new experiments with sincerity and the 'real', I instead argue that this aesthetic turn has economic determinants. Since the 1970s, the middle-classes of North America and Europe have seen their living standards eroded and have increasingly faced the same insecurities of temporary work and renting as the working-class. Autofiction is frequently used by authors such as Dave Eggers, Megan Boyle, Heike Geissler and Lauren Oyler to narrate their experiences of downward mobility. I argue that the inclusion of the onomastic author-protagonist as a volatile blend of real and fictional, textual and extratextual, stable and unstable expresses the cultural and economic volatilities that have attended the gradual erosion of the North American and European middle-class and the bourgeois values that undergird it. Autofiction captures in a range of formally inventive ways both the personal experience and impersonal economic structures associated with downward mobility. Scholars have argued that in the nineteenth century realism gave downwardly mobile writers a form in which the world came to seem more stable and solid. Today, I argue, this aesthetic role has largely fallen to autofiction. Its central focus being the inner world of the self rather than the outer world of tangible things, autofiction expresses a class that tends to understand downward mobility less overtly through the disappearance of a solid world of commodities and property but instead through the oscillations of "human capital", an ideological dominant during the neoliberal period. The promise of stability is found in the literary construction of an authentic image of selfhood, in ways that often register the social phenomenon of "self-branding". These rich portrayals of the author's self-image often substitute for sensuous descriptions of the outer world. Unlike literary forms such as naturalism that in many instances demonstrated the bourgeoisie's mastery over reality by mapping the world of objects in luscious detail, autofiction tends to withdraw from sensuous experience. To varying degrees, the fictional worlds that feature in this thesis are sparse, even minimalist, and certainly do not open out into the thick descriptions of reality readers have come to associate with bourgeois realism. This absence, I argue, displays a terminal point in the fortunes of the middle-class, whereby the tangible world of property can no longer be relied on to offer stability. Most writers of autofiction came of age when the aspirational promises of the bourgeois 'good life' were ubiquitous in popular culture, even as the economic prospects of the middle-class had entered decline, leaving a cleavage between expectations and lived reality. As this thesis shows, disappointment, regret and disorientation are among the most persistent affective experiences of the downwardly mobile. Autofiction's undecidable facticity, its tendency to drift between the real and the imaginary, lends itself to narratives that are very often about reality not turning out as expected. Contemporary autofiction is often a fiction of economic trauma, insecurity and immobility.