text: Kenneth Arrow and John Pratt developed a measure of how people react to this thing based on the ratio ofthe utility function's second derivative over its first derivative.
full_question: Kenneth Arrow and John Pratt developed a measure of how people react to this thing based on the ratio ofthe utility function's second derivative over its first derivative. Individuals whose behavior can be explained bya linear utility function are indifferent towards it. Beta is the ratio of this quantity for a specific asset over thisquantity of the entire market. Its price for a given portfolio is the expected excess return of the portfolio overits standard deviation. Frank Knight treated this quantity as something measurable to distinguish it from uncertainty.The variance of an asset's return is used to measure this thing, which treasury bonds are usually assumedto be free of. For 10 points, name this measure of how likely an investment is to fail. 
first_sentence: Kenneth Arrow and John Pratt developed a measure of how people react to this thing based on the ratio ofthe utility function's second derivative over its first derivative.
raw_answer: risk [prompt on uncertainty; do not accept "ambiguity"] 