The question asks to identify which statement is NOT a fundamental property of indifference curves used in microeconomics.

Analyzing Indifference Curve Properties

Let's examine each option:

• Negative Slope: This is a standard property. Indifference curves slope downwards from left to right, indicating that to consume more of one good, one must consume less of another to maintain the same level of satisfaction. This reflects the trade-off between goods.
• Concavity to the Origin: This is NOT a standard property. Typically, indifference curves are convex to the origin. Convexity arises from the assumption of a diminishing marginal rate of substitution (MRS), meaning consumers are willing to give up progressively less of good Y to obtain one more unit of good X as they consume more X. Concavity would imply an increasing MRS, which is generally not observed for typical goods (especially imperfect substitutes).
• Non-Intersection: This is a crucial property. Indifference curves for the same consumer cannot intersect. If they did, it would imply inconsistent preferences, violating the assumption of transitivity (if A > B and B > C, then A > C).
• Higher Satisfaction on Upper Curves: This property stems from the assumption that 'more is better' (non-satiation). Indifference curves located further away from the origin represent combinations with larger quantities of goods, thus providing a higher level of utility or satisfaction.

Conclusion on Non-Property

Based on the analysis, the statement that indifference curves are concave to the origin for imperfect substitutes is incorrect. The standard assumption is convexity due to diminishing MRS.

Therefore, the correct option is the one stating concavity as a property.