Stock portfolio selection is a classic problem in finance, and it involves deciding how to allocate an institution’s or an individual’s wealth to a number of stocks, with certain investment objectives (return and risk). In this paper, we adopt the classical Markowitz mean-variance model and consider an additional common realistic constraint, namely, the cardinality constraint. Thus, stock portf...

We consider the dynamic portfolio choice problem in a jump-diffusion model, where an investor may face constraints on her portfolio weights: for instance, no-short-selling constraints. It is a daunting task to use standard numerical methods to solve a constrained portfolio choice problem, especially when there is a large number of state variables. By suitably embedding the constrained problem i...

The research on computational advertising so far has focused on finding the single best ad. However, in many real situations, more than one ad can be presented. Although it is possible to address this problem myopically by using a single-ad optimisation technique in serial-mode, i.e., one at a time, this approach can be ineffective and inefficient because it ignores the correlation between ads....

We derive asset-pricing and portfolio-choice implications of a dynamic incomplete-markets model in which consumers are heterogeneous in several respects: labor income, asset wealth, and preferences. In contrast to earlier papers, we insist on at least roughly matching the model’s implications for heterogeneity—notably, the equilibrium distributions of income and wealth—with those in U.S. data. ...

We investigate how the inability to continuously trade an asset affects portfolio choice. We extend the standard Merton model to include an illiquid asset that can only be traded at infrequent, stochastic intervals. Because consumption is financed through liquid wealth only, the presence of illiquidity leads to increased and state-dependent risk aversion. Illiquidity leads to under-investment i...

This paper studies portfolio choice and pricing in markets in which immediate trading may be impossible, such as the market for private equity and certain over-the-counter markets. Optimal positions are found to depend significantly and naturally on liquidity: when future liquidity is expected to be higher, agents take more extreme positions, given that they do not have to hold them for long wh...

We employ parametric and non-parametric cointegration to investigate the extent of integration between African stock markets and the rest of the world. Long-run correlation estimates imply very low association between the two. The two distinct cointegration approaches confirm the latter through recursive estimation. The implication is that global market movements may have little impact on Afric...

We introduce a money demand motive in a life-cycle portfolio choice model and estimate the structural parameters that can generate limited stock market participation and plausible holdings of money, bonds and stocks. The model predicts an increase in bond holdings over the life cycle, and a declining share of money in portfolios as wealth increases. Both predictions are consistent with the data...

This paper examines the effect of the labor-leisure choice on portfolio and consumption decisions over an individual’s life cycle. The model incorporates the fact that individuals may have considerable flexibility in varying their work effort (including their choice of when to retire). Given this flexibility, the individual simultaneously determines optimal levels of current consumption, labor ...