Yisong S. Tian

We find evidence of geographic segmentation in the market for top executives and identify industry co-agglomeration as the primary driver. When top executives move from one firm to another, nearly 40% of the moves are between local firms, which is more than five times greater than predicted by available employment opportunities. Furthermore, these local moves are dominated by moves among firms in co-agglomerated industries. While the strong local move bias is also accompanied by local co-movement in the compensation of top executives, the co-movement is driven by local peers in co-agglomerated industries only but not by other local peers.

We identify a problem in the widely used binomial option pricing model when it is used to value options on an asset paying continuous dividends. It does not value pairs of European spot and futures options consistently even though they are theoretically equivalent. The inconsistency arises from the way dividend yield is incorporated into the jumps and probabilities. In addition, the model also has the tendency to undervalue American options due to suboptimal early exercise decisions. While the lingering effect of this problem diminishes asymptotically, it is nonetheless a concern for someone just beginning to learn the model or in applications where the use of a sufficiently large binomial tree is not practical or economical. We propose a simple modification to solve the problem and demonstrate the effectiveness of the solution.

Prior research suggests that Asian stock options provide stronger managerial equity incentives than traditional stock options do, holding the cost of the option grant constant. Although this is true on the grant date, it is not over the life of the option grant. Very little of the initial advantage remains after two years because Asian stock options have diminishing incentive effects over time. A simple solution is to replace averaging over the option’s life with averaging over a moving window. We show that moving average options do not have the diminishing incentive problem and are effective in preventing managerial gaming.

We investigate how director networks impact IPO characteristics and find that firms with better-connected directors have higher IPO market valuation, more positive offer price revisions, higher first-day returns, more pre-IPO media coverage, and superior post-IPO stock performance. Director networks are beneficial to the share offering because corporate directors help facilitate information exchange with prospective investors, attract their attention to the IPO, and maintain and grow their interest after the IPO.

In this paper, we examine managerial gaming of different types of equity grants, both at the initial award of the equity grants (front‐end gaming) and the unwinding of the equity holdings in the future (back‐end gaming). We find that the potential gains from stock price manipulation vary substantially across different types of equity grants. While traditional stock option grants are less vulnerable to front‐end gaming, they are more vulnerable to back‐end gaming than other types of equity grants (e.g., restricted stock grants). To prevent or discourage managerial gaming, firms should preset all terms of the equity grant in advance and link its future payoff to average stock prices (e.g., by granting Asian stock options).

The binomial model is a workhorse of numerical option pricing. But the plain vanilla model produces a risk-neutral probability density for the stock price at expiration that becomes lognormal in the limit. This is consistent with Black–Scholes’ assumptions but not with actual option prices in the market. An alternative is an implied tree, which begins with the risk-neutral density extracted from the market prices for options with the desired maturity. The procedure constructs a lattice that is consistent with the desired distribution. An N-step tree has N + 1 terminal nodes, so fitting the tree to the market prices can be quite time consuming. The author proposes a simplification that greatly increases efficiency with negligible cost in accuracy. The trick is to calibrate only a subset of the terminal nodes to prices in the options market and fill in the other nodes by cubic spline interpolation.

We investigate the effect of CEO equity incentives on corporate spin-off decisions and find that CEOs with stronger equity incentives are, ceteris paribus, more likely to engage in corporate spin-offs (after correcting for potential endogeneity concerns). In addition to confirming previous findings that spin-offs are followed by positive announcement and long-run abnormal stock returns, we show that the level of the CEO’s incentives matters. In particular, we find that while low incentive firms have a stronger announcement effect, high incentive firms experience better long run stock performance following spin-offs. This is consistent with the disciplining effect of spin-offs since low incentive firms are also found to have more independent boards. While a stronger board may be more influential on key corporate decisions (e.g., spin-offs), better incentive alignment leads to superior long run performance. Our results thus suggest that while stronger corporate governance may serve as a substitute mechanism for managerial equity incentives in the short run, they are in fact complementary in the long run.

Traditional stock option grant is the most common form of incentive pay in executive compensation. Applying a principal-agent analysis, we find this common practice suboptimal and firms are better off linking incentive pay to average stock prices. Among other benefits, averaging reduces volatility by about 42%, making the incentive pay more attractive to risk-averse executives. Holding the cost of the option grant to the firm constant, Asian stock options are more cost effective than traditional stock options and provide stronger incentives to increase stock price. More importantly, the improvement is achieved with little impact on the option grant’s risk incentives (after adjusting for option cost). Finally, averaging also improves the value and incentive effects of indexed stock options.

Under efficient market hypothesis, option-implied forward variance forms a martingale and changes in forward variance follow a random walk. In this paper, we extract forward variance from option prices following a model-free approach and empirically test the random walk hypothesis. Although results from standard orthogonality tests support the martingale restriction, further results from autoregressive regressions seem to reject the martingale restriction as daily changes in forward variance are found to exhibit negative autocorrelation. However, this anomalous pattern of negative correlation is fully explained by illiquidity effects. Overall, the findings support the random walk hypothesis and informational efficiency of the options market.