Below are several examples that illustrate Keynes’ key criticisms and how modern economic processes often defy a simple labour-based explanation of value:

1. Consumer Preferences and Market Demand
    Imagine the launch of a new smartphone. The device requires a certain number of labour hours to assemble its components, yet its market price is driven by consumer expectations, brand perception, and the hype surrounding new technology. Keynes would argue that while labour contributes to production cost, the selling price is largely influenced by factors such as demand and consumer sentiment rather than the measured labour time alone.

2. The Role of Capital and Speculative Elements
    Consider a new business startup in the technology sector. Although the product has an identifiable labour input, much of its valuation comes from investor expectations, potential market growth, and the marginal efficiency of the capital invested. Keynes pointed out that such uncertainty and speculative behavior in capital markets mean that the stock or company value cannot be accurately determined just by evaluating the labour hours put into developing the product.

3. Technological Change and Productivity Gains
    Take the example of two factories producing the same commodity. One uses traditional labour-intensive methods while the other employs advanced automation. The labour theory of value might suggest that the product of the labour-intensive factory has higher value because more human effort is involved. However, from a Keynesian perspective, technological innovation reduces production time and increases output, meaning that the market value might diverge significantly from the amount of labour required under older methods.

4. Uncertainty in Value Determination
    In financial markets, asset prices often fluctuate due to investor psychology, risk assessments, and future expectations. For instance, the value of a company’s shares is not directly linked to the exact number of labour hours expended in its operations. Keynes argued that in such cases, the interplay of expectations and uncertainty is far more critical in shaping value than the labour input, emphasizing the dynamic and multifaceted nature of price formation.

These examples reflect Keynes’ view that while labour remains an important factor in production, a comprehensive understanding of value requires incorporating demand conditions, capital dynamics, technological change, and the inherent uncertainty of modern markets.