We introduce dynamic agency into the neoclassical q theory of investment. Costly external financing arises endogenously from dynamic agency, and influences firm value and investment. Agency conflicts drive a history-dependent wedge between average q and marginal q, and make the firm's investment policy dependent on realized profits. A larger realized profit induces higher investment, and hence a larger firm. Investment is relatively insensitive to average q when the firm is "financially constrained" (i.e. has low financial slack).Conversely, investment is sensitive to average q when the firm is relatively "financially unconstrained," (i.e. has high financial slack). Moreover, the agent's optimal compensation is in the form of future claims on the firm's cash flows when the firm's past profits are relatively low and the firm has less financial slack, whereas cash compensation is preferred when the firm has been profitable, agency concerns are less severe, and the firm is growing rapidly. To study the effect of serial correlation of productivity shocks on investment and firm dynamics, we extend our model to allow the firm's output price to be stochastic. We show that, in contrast to static agency models, the agent's compensation in the optimal dynamic contract will depend not only on the firm's past performance, but also on output prices, even though they are beyond the agent's control. This dependence of the agent's compensation on exogenous output prices (for incentive reasons) further feeds back on the firm's investment, and provides a channel to amplify and propagate the response of investment to output price shocks via dynamic agency.

Agency problems limit firms’ access to capital markets, curbing investment. Firms and investors seek contractual ways to mitigate these problems. What are the implications for investment? We present a theory of a firm’s investment dynamics in the presence of agency problems and optimal long-term financial contracts. We derive results relating firms’ investment decisions, current and past cash flows, firm size, capital structure and dividends. Among the results, optimal investment is increasing in current and past cash flow; and optimal investment is positively serially correlated over time (after controlling for investment opportunities). These results hold for a range of agency problems.

We develop an agency model of financial contracting. We derive long-term debt, a line of credit, and equity as optimal securities, capturing the debt coupon and maturity; the interest rate and limits on the credit line; inside versus outside equity; dividend policy; and capital structure dynamics. The optimal debt-equity ratio is history dependent, but debt and credit line terms are independent of the amount financed and, in some cases, the severity of the agency problem. In our model, the agent can divert cash flows; we also consider settings in which the agent undertakes hidden effort, or can control cash flow risk.

Self regulation is a feature of a number of professions. For example, the government delegates aspects of financial market regulation to self-regulatory organizations (SROs) like the New York Stock Exchange and the National Association of Securities Dealers. We analyze one regulatory task of an SRO, enforcing antifraud rules so agents will not cheat customers. Specifically, we model contracting/enforcement as a two-tier problem. An SRO chooses its enforcement policy: the likelihood an agent is investigated for fraud and a penalty schedule. Given an enforcement policy, agents compete by offering contracts that maximize customers’ expected utility. We assume the SRO’s objective is to maximize the welfare of its members, the agents. We show that the SRO chooses a more lax enforcement policy—meaning less frequent investigations—than what customers would choose. A general conclusion is that control of the enforcement policy governing contracts confers substantial market power to a group of otherwise competitive agents. We also investigate government oversight of the self-regulatory process. The threat of government enforcement leads to more enforcement by the SRO, just enough to preempt any government enforcement.

Numerous rules mandate the disclosure of information. This article analyzes why such rules are enacted. Specifically, (i) why wouldn't firms voluntarily disclose their private information; and (ii) given that voluntary disclosure would not be forthcoming, who has the incentive to lobby for mandatory disclosure rules? Previous analyses of disclosure assume that all customers understand the disclosures that can be made. A key result in these analyses is that there is no role for mandatory disclosure. Either voluntary disclosure is forthcoming or if it is not, no one is better off with mandatory disclosure. We analyze a market in which not all customers understand the disclosures that can be made. We show that if the fraction of customers who would understand a firm's disclosure is too low, then voluntary disclosure may not be forthcoming. In this case, mandatory disclosure benefits some (possibly all) customers and may also benefit firms. Thus we identify a motive for someone to lobby for such rules. Our results suggest that we should find mandatory disclosure rules with regard to information that is relatively difficult to understand.

Regulating insider trading lessens the adverse selection problem facing market makers, enabling them to quote better prices. An optimal enforcement policy must balance these benefits against the costs of enforcement. Such a policy must specify (i) the conditions under which the regulator conducts an investigation, (ii) the penalty schedule imposed if an insider is caught, and (iii) a transaction tax to fund enforcement. We derive the policy that maximizes investors' welfare. This policy entails investigations following large trading volumes or large price movements or both. Insiders caught making large trades are assessed the maximum penalty, but small trades are not penalized. Given this policy, insiders trade most aggressively on news with an intermediate price impact but refrain from trading on moderate or extreme news.

Investment advisory firms and brokerage firms hire analysts to uncover profitable securities investment opportunities. Then these firms sell the information (either directly or indirectly) to others. Why? Given that the information has value, why do these firms not keep the information to themselves and trade solely for their own accounts? Because of competition, information is more valuable when fewer people trade on the information. This paper shows that selling information is a strategic response by competing informed traders. Specifically, it is a means for informed traders to commit to trade aggressively, thereby inducing other informed traders to trade less aggressively.

Financial market regulations require various "insiders" to disclose their trades after the trades are made. We show that such mandatory disclosure rules can increase insiders' expected trading profits. This is because disclosure leads to profitable trading opportunities for insiders even if they possess no private information on the asset's value. We also show that insiders will generally not voluntarily disclose their trades, so for disclosure to be forthcoming, it must be mandatory. Key to the analysis is that the market cannot observe whether an insider is trading on private information regarding asset value or is trading for personal portfolio reasons.

With dual trading, brokers trade both for their customers and for their own account. We study dual trading and find that customers who are less likely to be informed have higher expected profits with dual trading while customers who are more likely to be informed have higher expected profits without dual trading. We also examine the effects of frontrunning. We test the major empirical implications of our model. Consistent with the model, dual traders earn higher profits than non-dual traders, and customers of dual-trading brokers do better than customers of non-dual-trading brokers.

We analyze several aspects of the debate on insider trading regulations. Critics of such regulations cite various benefits of insider trading. One prominent argument is that insider trading leads to more informationally efficient stock prices. We show that under certain circumstances, insider trading leads to less efficient stock prices. This is because insider trading has two adverse effects on the competitiveness of the market: it deters other traders from acquiring information and trading, and it skews the distribution of information held by traders toward one trader. We also discuss whether shareholders of a firm have the incentive to restrict insider trading on their own.

In this paper a party with private information can verifiably disclose some, but not all, of his information. The optimal amount of discretion to allow the informed party is studied. That is, should the informed party be allowed unlimited discretion in choosing which elements of his information set to disclose, or should restrictions be imposed that limit this discretion? The model is formulated in the spirit of a "persuasion game." It is demonstrated that under certain circumstances, rules that limit discretion increase the informativeness of disclosures and thus improve economic decisions.

This paper develops a model of the relationship between investment decisions by firms and the efficiency of the market prices of their securities. It is shown that more efficient security prices can lead to more efficient investment decisions. This provides firms with the incentive to increase price efficiency by voluntarily disclosing information about the firm. Disclosure decisions are studied. It is shown that firms may expend more resources on disclosure than is socially optimal. This is in contrast to the concern implicit in mandatory disclosure rules that firms will expend too few resources on disclosure.

The medium of exchange in acquisitions is studied in a model where (i) bidders' offers bring forth potential competition and (ii) targets and bidders are asymmetrically informed. In equilibrium, both securities and cash offers are observed. Securities have the advantage of inducing target management to make an efficient accept/reject decision. Cash has the advantage of serving, in equilibrium, to "preempt" competition by signaling a high valuation for the target. Implications concerning the medium of exchange of an offer, the probability of acceptance, the probability of competing bids, expected profits, and the costs of bidders are derived.

This article develops a model of the takeover bidding process. The model can be described as a form of auction in which a bidder can acquire costly information after the bidding has begun. Implications concerning the interrelationships between bidders' and targets' profits, bidders' initial offers, single and multiple bidder contests, and the effects of takeover legislation are developed. Additionally, the model provides a rationale for bidders to make high premium ("preemptive") initial bids, rather than making low initial bids and raising them if there is competition.

Consider a principal who hires an agent, e.g., a broker is hired to fill stock orders. The outcome may be good or bad, e.g., the orders may be filled at favorable or unfavorable prices. A bad outcome may simply reflect bad luck or it may result from the agent defrauding the principal. How is the agent’s incentive to defraud the principal restrained? With a dynamic costly-state-verification model we examine two possibilities: (i) reputational penalties, meaning that principals can choose not to transact with an agent who has a bad history even if there is no evidence of fraud; and (ii) investigations, meaning that at a cost, an agent’s performance can be directly checked for fraud. Reputational penalties have no direct cost but they are imprecise in the sense that an agent can be penalized even if it was just bad luck. Investigations are costly but precise in the sense that an agent is penalized only if he is found to have committed fraud. We examine how principals would balance the two ways of controlling an agent’s incentives. Then we examine the incentives of agents to form a self-regulatory organization to conduct it’s own investigations of agent performance and to penalize agents who are caught cheating. The threat of SRO investigations can enhance agents’ welfare but reduce the welfare of principals. In effect, SRO investigations can inefficiently – from the principal’s perspective – crowd out reputational penalties.