Investment behaviour and “bull & bear” dynamics: modelling real and stock market interactions

In this article, we develop a simple behavioural macrodynamic model in continuous-time with the purpose of investigating the interaction of the real economy and the financial markets. Building on Westerhoff (Discret Dyn Nat Soc, 2012), we improve the specification of aggregate demand by distinguishing between consumption and investment expenditure and assuming that the latter is determined by the flexible accelerator principle. We remove the ad hoc nonlinearity in the fundamentalist behavioural rule and allow the composition of the population between chartists and fundamentalists to be endogenously determined. The resulting nonlinear dynamic systems are shown to generate various dynamic regimes, among which the coexistence of periodic attractors with interesting economic implications. Endogenous investment and stock market dynamics emerge, procyclical to each other, reflecting the interaction of induced investment with alternating waves in speculators’ sentiments. We show that a strong investment accelerator might be a crucial force generating fluctuations that, on the one hand, are transmitted and amplified by chartists and, on the other hand, are contained by fundamentalists.

     

Construal level and collaborative consumption: An exploratory approach

What motivates the participation in collaborative consumption, a part of the economy that will move 300 billion dollars by 2025? The literature presents external factors to the consumer as a form of incentive or limitation, such as economic opportunity, search for a sustainable society or emergence of a marketplace with no regulations. A few quantitative articles focused on understanding this access phenomenon, by analyzing the consumer as the main subject of research. However, it is possible to analyze this behaviour in the light of a theory that has not yet being explored within the collaborative consumer literature: The Construal Level Theory (CLT). This article aims to demonstrate that CLT presents a plausible explanation for adoption and access to collaborative consumption. The CLT's main idea is that consumers develop their interpretations on two levels: a higher one, focused on more abstract and simple situations; and a lower one, where judgments are conducted more concretely and complexly. Studies on CLT have shown that attitudes are usually constructed at high levels of interpretation, while behaviour is interpreted within lower levels. We propose that collaborative consumption can be reflected by consumers’ high or low levels and so defining the consumer's behaviour in this context.     

Demand‐led growth with endogenous innovation

This paper contributes to the recent macro‐dynamics literature on demand‐led growth, drawing upon the seminal idea that the implications of Harrodian instability may be tamed by a source of autonomous expenditure in the economy. Contrary to the other contributions in this literature, real autonomous expenditure is not growing at an exogenously given rate, and partly consists of a flow of profit‐seeking R&D and innovation expenditures raising labour productivity through time. If the state of distribution, hence the wage share, is exogenously fixed and constant, the model gives rise to dynamics in a two dimensional state space, that may converge to, or give rise to a limit cycle around, an endogenous growth path. An exogenous rise of the profit share exerts negative effects on long‐run growth and employment, showing that growth is wage led.