Bibliography Style Vignette in R

Question

I am developing vignette for a package in r and wish to include some citations in the document. I want the citations to look like this `Author (year) unfortunately what I have is (Author year)

---
title: "MNP: My New Package"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{MNP}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
bibliography: "economia.bib"
logo: logo.png
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup}
library(MNP)
```

## Statement of the Research Problem

### Introduction

- [@Hall1995] and [@Politis2004] 

This is what I have